The Merlin is a restricted class built to a set of rules rather than a plan. Thus the hulls and rigs of individual boats vary within given limits, enabling you to tailor your boat to suit your weight, sailing water and temperament. If you and your crew weigh 18 stone combined, there is a Merlin for you. Similarly, if you weigh 28 stone there is a Merlin for you. No other dinghy is as tolerant of as wide a range of crew weights. Merlin Rockets recognise that WE are not one-design people!

Husbands and wives sail Merlins (and can win championships), so do fit youngsters, hefty blokes, and wily grandads. Modern rig controls have made female crews more competitive than ever before.

If you want to race at your local club, there is a wide range of suitable designs. One of the things you will notice as you walk round the dinghy park is that Merlins are wider than other boats. This gives an efficient base for today's powerful rigs, and gives tremendous sitting-out power so you can drive the boat hard in a blow.

For these reasons, we would not recommend an older, narrow hull, unless you sail on rivers such as the Thames or the Trent where low wetted area and the ability to tack on a sixpence keeps it competitive. However, you will not need the latest speed machine. Plenty of people pick up club trophies sailing older Winder mk1 and 2 Canterbury Tales, or even older wooden Tales or Let it Ride.

If you want to get amongst the prizes on the Silver Tiller circuit, or at the National/Inland Championships, you will need a stiff hull, sound foils and good sails. If you only travel for the scenery, the beer and the camaraderie, you will be welcome whatever you sail.

After decades of development the competitive Merlin hull has standardized around the Canterbury Tales shape over the last 15 years. Interestingly this shape – despite incremental reductions to the rocker line – has been sailed competitively by the entire weight range whereas before there were accepted lightweights boats and heavyweights boats. Rig control in the form of carbon spars and the one string control system has taken over as the factor that determines how much weight you can sail with, and for many years the lack of a hull considered to be a viable alternative forced everyone down the Tales path. For this reason weight carrying ability is not talked about much with regard to new designs – the guys at the front out on the circuit generally weigh in between 20 and 25 stone.

At the time of writing at least one new design has tooling under construction to produce FRP hulls, and wooden or foam planked versions of another are available.

Current Trends.

Taking hull development out of the equation for a moment the appearance of several quite radical boats sporting many new ideas has precipitated a fairly significant step change in boat fitting out. Changes to the sail plan have also been tried over the last few years and inevitably the better ideas have been more widely adopted. The majority of these ideas have been aimed at making the boat easier to sail fast rather than just faster, and can be retrofitted to older boats with varying levels of cost depending how far you go. "Lazy guys", reliable self launching spinnaker pole systems and working pump action spinnaker halyards have probably made the biggest difference to boat handling ergonomics, but along with X/Y jib sheeting add significantly to the complexity of the boat. Beware of poorly installed systems if buying second hand.

Foils were played with quite extensively and while a longer, high aspect rudder seems to have found favour the high aspect board hasn't been universally adopted and the fleet has largely reverted to variants of the old "Spitfire wing" shape. There are notable exceptions to this who do not go slowly.

Sail plan.

The Merlin Rocket sail plan had been a 2.8m jib, paired with a mainsail luff of 5720mm and a foot of 2503mm since the mid 1980s. The jib was tacked behind the chute. It should be remembered that back in those days the spinnaker was significantly smaller and the pole was only 6ft long.

The Genii design started the change with a host of ideas and combinations tried based around a bow tacked jib. This stabilised at a 3.12m jib with a smaller mainsail foot of 2393mm set on a standard 5720mm luff. Jon's reasoning behind the change was that the old rig with the small spinnaker needed the large main to get the boat downwind. The modern spinnaker and long pole frequently saw the mainsail flogging on a reach which is inefficiant and creates a lot of drag. Jon reasoned that with the larger spinnaker he could now reduce the size of the mainsail by shortening the foot which would reduce the sheet load, shorten the leech of the mainsail allowing more rake to be used and also reduce the tendancy of the sail to need to be flogged on a reach. 

The bow tack was percieved to be the most significant change by most of the fleet, who were possibly reluctant to try more then one change at a time! The first Winder boats built this way were 3777 and 3787, both notable for the different approach their owners took to this change. The former initially used a rig designed specifically for the boat with a slightly larger mainsail, while the latter uses a Genii rig with the jib altered slightly to suit the different deckline. All of the main sailmakers have had a go at designing their own rigs for this arrangement. A very short luff 2.8m jib paired with a standard design mainsail hes become popular as it is an easy and relatively inexpensive change to make. In the 2020s the rig on new boats seems to be stabilising around a jib of around 3.1m and a mainsail foot of around 2400mm on a standard 5720 luff. Most boats newer than 3780 have bow tacked jibs either as built or retrofitted. It must be pointed out that the chute tacked arrangement isn't outclassed, and some owners have adopted a larger jib/smaller main combination by making the jib luff longer - there are many ways of skinning a cat!

The other advantage of the bow tack is that it allows a larger spinnaker chute. This is perhaps negated somewhat by the jib now being in the way of the emerging spinnaker, but the fit out developments of the pump spinnaker and self launching poles help with this. Chute position has also got variations with an even larger chute set slightly further back and to port being tried on several new boats.

The final thing of note is that the sail plan has moved forwards and this has altered the feel of the boat. Again of interest is that David Winder moved the board forward in Canterbury Tales when he started building. In the author's opinion these developments have put the balance of the boat back to where it was in the older wooden and composite boats of this design.

The current designs.

Prices start at around £5000 for a Mk4 Winder in sound condition but in need of some updates.

Winder Mark 5

This is a further modification of the Mk4. The waterline has been pushed in through the whole length of the boat, and the rise of floor is taken to the extreme maximum possible. The first boat built with this modification is 3732. Further development was taking place with foils, and a few of these boats sport a slightly longer case ready to accept a new shape centerboard which appeared in the form of a hatchet board with input from Dave Hollam.

Further changes to the hull shape have now appeared. Boats after 3780 have a flat aft run and several boats after 3800 were altered after moulding to have a widened waterline under the mast as well as wider, flatter garboards aft resulting a slightly different transom shape. This later modification will probably become known as the 5b and was tried first on 3691 by Mike Calvert. Mike wanted to bring the Tales shape closer to that of its Let it Ride derivative which was very successful in the 1990's. Most of the percieved strengths and weaknesses of the Let it Ride appear to be replicated and the boats perform well without outclassing the previous shape. I think its fair to comment that the Let it Ride was not renowned for its ability to carry weight and the older shape may prove to be better for heavier teams.

3781 The Force Awakens is worthy of a mention as David wanted to try out a boat with maximum beam from the shroud base all the way aftto the transom. This boat started life as a standard mk5 in the standard mould and was drastically atlered before the mouldings were assembled. On the water it proved to be very fast on windy reaches but hard work short tacking due to the extra wetted area when heeled.

 Winder Mark 4

In an experiment aimed at trying to get some more bite when sailing to windward two Mk2 boats (3611 and 3620) were altered by dropping the bow by 20mm. On later boats a frame was inserted in the section aft of the centerboard case to bend the mould straighter. Bilge keels were also an area of experiment, a few boats were built with them extended all the way aft to give more buoyancy and increase the planing surface. Some later boats also feature a completely flat run aft.

A number of older Mk1s and 2s have had the bow and bilge keels altered to the Mk4 shape. To date no one has altered the aft section.

Around sail numbers 3661 – 3679 some boats have been further modified with increased volume in the bow and the run to stern flattened. The bilge keels have also been moved aft and faired into the stern. While this mod was successful on the water this did not catch on, and only about 10 boats were built with this modification. At least one Mk1 has been altered to this shape, and one boat altered back to a straight Mk4. Their failure to achieve popularity is probably due in part to the imperious performances of Roger Gilbert and James Stewart in a Mk4 at the Looe and Pwllheli championships in 2006/07.

A well kitted out Mk4 in good condition can still win the big events in the right hands. All the basics will be in place but the boat will probably need some rigging work if its as original. A new mast may also be desirable and a boat that already has one will be more sought after.


While David Winder has been busily refining the Canterbury Tales, it’s creator - Jon Turner - made a return to the class in 2010 with this design developed in conjunction with Jonathon Lewis and Phil Morrison.

Perhaps more radical in appearance than underwater shape it bears the DNA of Turner’s previous successful design work, yet is a substantial departure from anything that has come before.

The Genii is reported to have slimmer sections at the waterline than any previous design. On introduction it was also wider than any existing design: its maximum beam at deck level extends from the shrouds all the way to the transom. The Genii has increased freeboard, which gives a finer frontal area for better wave penetration upwind. The carbon deck is flat for increased comfort and reduced side profile. Another innovation is the low, maximum-length aft tank, which gives a clean, open layout in the helm’s area, as well as substantially increased buoyancy for exceptionally quick draining after a capsize.

When Dark Star first appeared in 2010 the boat initially caused a little head scratching, as well as controversy as the bilge keel arrangement fitted was felt not to be within the spirit of the class rules. Further moves down this path have now been prevented by a rule change. Initially the performances of the two boats Jon built were not all that promising, though Dark Star turned a few heads up first beats at the Penzance champs in 2010 – little has been seen of this boat since. In subsequent years much time, effort and development has been put into Shabazzle and the boat has got faster and faster to the extent that tooling for moulded hulls was constructed.

Genii Evolution
After deciding that he was happy with the hull shape Jon built 3767 in foam and glass on frames in the same way as Dark Star and Shabazzle, but with standard 6mm lands. A mould was taken off this boat, and paired up with deck and internal mouldings taken off a very chopped up Shabazzle. To date a handful of boats plus prototype have been built. It was a very long time coming but the potential of this design was finally realised with a championship win for Nick Craig and Alan Roberts at Pwllheli in 2017. 3807 won the most races at Mounts Bay in 2022 but wasn't consistent enough to take the event. Early examples have started to appear second hand at good prices for their sail number.



In 2018 John Fildes approached Jo Richards to design a new Merlin Rocket but being very busy and short on time Jo agreed to draw the hull lines and position the mast and board only. After that it was up to John to decide the rest, and John sought the assistance of Simon Hipkin to build the project with him.

Rockatross is a low rocker boat and absolutely minimum rise-of-floor, however the crew should be prepared to move right back to the transom if required, to keep the bow out, hence the almost full width stern. The hull is as shallow as possible at mid length to push the rise-of-floor measurement up, and as a consequence reduce the waterline beam. The plank run on a Merlin is a compromise in different conditions and Jo is a firm believer in keeping some width on the garboard and twisting this up to the stem which has the effect of twisting some of the water down under the boat rather than pushing it out to the sides. It is less distance for the water to travel and provides ‘cheap lift’. 

Rockatross is slightly reduced in freeboard compared to some other Merlins to try to keep the aerodynamic drag down, and the maximum beam is carried as far into the crew’s area as possible to maximise righting moment. This means that where the crew sits next to the shrouds the boat is 180mm wider than a Canterbury Tales, giving a significant righting moment gain upwind.

The internal design is a mixture of ergonomics, aerodynamics and interlinking of the structural components to create stiffness, and while trying to do something a bit different, it was important to try and keep some of the features similar to the other modern Merlins so that crews aren’t completely unfamiliar with it. The design brief was to end up with a clean, spacious boat so you’re not forever tripping over ropes, and one which is easy for even the shortest of crews to cross

The reverse bow and having no gunnels at the front reduce windage and combined with a long upward sloping foredeck helps the air flow into the leeward side of the jib, as well as helping to endplate the jib.

Only one boat has been built to this design so far. The boat has at times performed very well indicating it does have potential but its been inconsistent. A proper campaign in the hands of a top helm will make or break it.

Digital Native

A new design in 2023 by Gavin Willis and Nigel White.

The rather radical boat appeared in the boat park at Brading Haven for the 2023 championships. Unfortunately - by Gavin's own admission - the boat had hit the water but once and they spend as much time fitting it out as sailing it, not helped by the weather during the week!

Under water the boat features inverted garboards that continue well forwards towards the bow to try to create a tunnel hull. It is hoped that the tunnel will force the water pressure inwards to create lift rather than forcing it outwards and making a wave. The inverted garboards also permit a narrower waterline as the point of measurement for the rise of floor is raised. The side effect - and percieved downfall of previous attempts to do the same thing - is that it reduces buoyancy in the middle of the hull and makes the ends of the boat more buoyant - much effort has gone in to try to mitigate this. 

The boat is intended to carry more weight than contempory designs.

Does it work? We will see!

Older designs

These designs whilst still competetive within their peer group are now considered unlikely to win the chamopionships. However they are excellent entry level boats and very competant club racers even capable of taking an open meeting if well sailed. Prices start from about £2000 for a boat in good racing condiotion.


Guy and David Winder obtained the Ian Holt designed, Jon Turner built Canterbury Tales hull mould in 1998 to prevent it from being destroyed. At the time the class was at an all time low, with a handful of beautifully built, but very expensive wooden boats being built each year. The class association sounded out it’s members at the Abersoch championships about funding the tooling for deck and internal mouldings, but such was the support for this proposal at the class AGM that Guy and David decided to proceed as a commercial venture, it being David’s project. The first boat out of the moulds won the Weymouth championships in it’s first year.

Since then boats by Winders have taken the class by storm, and they have become the industry standard Merlin Rocket – a strange situation in a development class!

Age seems to be little barrier with these and it is rig and fit out that holds these boats back rather than the shape of their hull!

Winder Mark 1 Canterbury Tales

These are much the same as the older composite boats that Jon Turner built in the 1990s, but with a glass deck and internal mouldings. Hull wise, the bow has been straightened out slightly, rise of floor pushed in to minimum, centreboard moved slightly forwards, and the gunwhale profile altered to accept the glass deck.

These boats proved an instant success and 38 were built. If still rigged as supplied its fair to say that these are now at a little disadvantage but they are still successful at clubs all over the country in the right hands. 

Winder Mark 2

The overall shape is the same as the Mk1 but with a few further refinements. The keel is faired into the transom, bilge keels rounded off and faired into the hull, and the whole mould was faired up to reduce drag and surface area. The centreboard case was also shortened.

Carbon decks and forward structure started to appear at the same time

15 boats were built, 3604 to 3624. The same caveats apply to these as the Mk1, but they are more likely to have been upgraded over the years. Over half were changed to Mk4 shape.


Refinements in both hull shape and fit out have kept the Winder product at the forefront of class development in spite of the age of the hull mould. The majority of the later hull modifications can be made to existing hulls which is a further attraction, but it is unlikely to be cost effective to buy one of these with the objective of turning it into a championship winner. With prices starting at approximately £2000 for an unmodified mk1 with an original rig its never been so cheap to own a race winning Merlin Rocket! Beware of non standard attempts to modernise the fit out, particularly flawed one string conversions.


This design came about as a result of further work by Kevin Driver and input from Phil Morrison. It is the only Merlin Rocket so far that has been designed “from the ground up” to be built in FRP, and has a very innovative internal layout. When they first appeared they were also the lightest Merlin Rockets being built, although the other builders have now caught up.

The idea was to slightly modify the Let it Ride shape to give a more “all round” design. If you look at an EZ roller hull there is noticeably more rocker at the bow than the other designs being built today. There is also more rocker aft of the centreboard case, though the garboards are still very straight. This gives a hull that tacks better than the Let it Ride and is rather easier to get the best out of in lighter winds. Planing performance is very good, provided the boat is held absolutely flat. It is at it’s best in a sub force 3/4 and was a very good Salcombe boat.

On the water they were a success from the start, but have never really achieved popularity with only 11 being built to the original shape. They seem to go best with about 22 to 23 stone on board.

It can be summed up as being a good, competitive hull of it’s time but these were built much lighter than the Winder hull and they have not aged as well. You’re likely to find one either slightly cheaper than or on a par with a Mark 2 Winder, and the EZ Roller is likely to have a higher specification rig as no expense was spared in putting most of these boats afloat. 

The tooling is now in the hands of Gingerboats and one modified hull has been built.


Will Rainey felt that the design could be fettled and asked for a number of modifications to two of his boats. In 3629 the entry was made finer to help the boat sail through a chop. With 3660 he asked to go even further, dropping the transom 8mm and the stem about 28mm. This boat has no rocker at all aft of the centreboard case, and is reported to be much closer to the original Let it Ride shape. In this form it turned out to be strictly for lightweights (20 stone). Subsequent reshaping has been carried out by Nick Turner (Formerly of Rowsell & Morrison) on the bow section and the bilge keels.

The Woodies.

These are among the last of the designs built primarily in timber in the late 90's and early noughties. If well kept most will still perform well in the right hands, particularly inland where the relative (Age induced!) lack of stiffness is less disadvantage. Prices start at around £1000


This design marked the return to the class of Keith Callaghan who designed some very successful boats in the 1970s.

Several varieties of this design – the Hazardous – have been produced since 2007 and these represent the last of the wooden hulls to date. All share a similar overall pattern which compared to the Hexagon/Hysteria/Hazard line has the same fine entry, but flatter garboards forward, and a radically flatter planing run, to take advantage of the power developed by the sophisticated modern rigs. The first 2 new designs in this series, the Hazardous 140 and 170 designs, differed only in their weight carrying capability - the 140 was designed for a lighter crew (about 140kg, in fact), and had less curve in the aft run than the 170. Wetted surface area compared favourably with the 1970s hulls. No UK based boats were built to either of these designs, but several plans were sold abroad.

In 2009 the Hazardous Zero-9 was drawn. It is designed to carry 7-10kg more weight that the Canterbury Tales, and with the centre of buoyancy set further aft, she will favour heavier helmsmen with lighter crews - often a typical Merlin crew combination. Wetted surface is about 1% less than Canterbury Tales, and hull draft is 16mm less. The waterline is finer to amidships, and a little wider towards the transom. A version for lighter helms, with less rocker in the aft run and more freeboard and beam aft of midships is also available. This design is called HAZARDOUS ZERO-9 LITE.

Several boats have been built in the UK to the Hazardous Zero-9 LITE, most notably 3708 which was built by Laurie Smart, builder some of the fastest wooden boats produced. This boat has been lent to some good sailors coming into the Merlin class and has produced some good results. It also had a good Salcombe week in the hands of it’s builder.


There are not many of these around, and only one has been built by a recognised Merlin Rocket builder. This boat had a good salcombe week in the hands of its builder, but despite Keith's efforts no current top Merlin sailor has been wooed into the boat. Timber construction was well and truly out of vogue when the boat was built which will not have helped. It's easy to consider the design a failure, but in truth its never been properly tried.


Designed and built by Laurie Smart, a handful of these boats were built between 1999 and 2001. The low numbers were more to do with the arrival of the low maintenance Winder product at around the same time than the speed of Lawrie’s boats - those that fell into the right hands proved to be at as fast across the wind range. All were built in wood, had carbon spars from new, and were well bullt.

The design is a development of Laurie’s earlier Smarty Pants design. If you compare it to the Canterbury Tales design you will see quite a number of differences:

Starting at the bow the stem is lower, the garboard planks are flat further forward. The keel line (rocker) is different to allow a narrower waterline all through the boat, and the run aft is narrower with more buoyancy low down. You will notice the transom shape is different too.

These boats have something of a following on the Thames, and again a well maintained example with a current rig could turn a few heads on the circuit if well sailed.


Two boats were built to this design, one in conventional timber, one in foam cored ply in a successful attempt to compete on weight with the FRP hulls. Principally the lines are based on his Make it So design but with a little less rocker, lowering of the stem and slightly narrower displacement water lines.

As both designer and builder Laurie can easily tweak his boats to suit individual client’s requirements.


A Canterbury Tales variant, Kevin Driver modified the standard Holt design in 1995 shortly after setting up his yard.

Let it Ride furthered the developments previously made by Jon Turner in his Heaven Sent design, itself a Tales variant. Compared with the Tales it has considerably fuller underwater sections forward of the mast, a flatter run with virtually no curve along the lands at the turn of the bilge, and increased beam at the transom. Meticulous attention to detail has enabled the constraints imposed by the rise-of-floor rule to be minimised. Two boats exhibit minor variations - 3537 XS has extra rocker aft, whilst 3543 Storm Cloud has a hollow run.

Boats to this design were thought to be faster downwind than Tales in marginal planning conditions. Claims that they are less manoeuvrable, are more difficult to handle in a blow, and possibly marginally slower in sub-planing mode are difficult to assess because the limited number of boats built to this design generally went to top sailors. They were generally sailed light.

They proved to be extremely successful, winning all the major events virtually unopposed until their owners were wooed by the new FRP hulls. They were sought after in their time and are rare – only nine were built. All of these were raced hard, but were maintained by their initial owners regardless of cost. If still in good condition one of these should still be able to get to the very front of the fleet in the right hands.

All were beautifully constructed in wood and will be equipped with a high specification rig of their day. They were generally not put together with cost in mind.


Designed in 1992 by Phil Morrison, the Thin Ice follows the thinking behind the Canterbury Tales, but aimed to give a very low wetted area and the ability to carry more weight than many of the contemporary designs.

Perhaps quicker-tacking and easier to sail than the Canterbury Tales, but thought to lack the straight line speed when planing. It proved to be quite fast, finishing second in the 1992 nationals, and winning Salcombe week in the same year.

Relatively few have been built, most of them by Rowsell & Morrison, with one or two owner-built examples. The Winder Canterbury Tales quickly replaced it in the late 1990s, but a well maintained example should still be successful inland in the right hands, especially if equipped with a modern rig. Again the interpretation of the plans by the builder will have a significant impact on actual hull shape.

Likely to be slightly cheaper than an equivalent Canterbury Tales, a Thin Ice could be a bargain for those a little on the heavy side for a Tales. Thin Ice has gone fast carrying up to 26 stone.


The Winder FRP Tales is much talked about above, but it should not be forgotten that the Canterbury Tales was drawn in 1988 and constructed in timber with an alloy rig. In many ways it was the Genii of it’s time with a return to the deck stepped rig being a radical feature.

Originally designed with Jon Turner in 1988, Ian Holt’s Canterbury Tales is the longest lasting competitive design ever. Jon Turner’s boats, both wooden and composite versions, produced most of the early successes but slightly modified boats by Rowsell’s and Alan Jackson at Chipstow Boatyard also have had their admirers. These boats can still be competitive and make excellent introductions to competitive Merlin Rocket racing, especially since most have been upgraded to carbon rigs.

In the late 1990s Alan Jackson built several modifications to this design which probably looked more radical than they really were as they sported spaceframes and cloth foredecks because Alan was trying to reduce the construction cost. Watermark and Honeymoon came first, but success largely eluded them. The more conventionally built Joyrider showed promise in the hands of Mark Barnes but was sold on quite quickly as Mark went back to B14s and largely club sailed thereafter. Ian Holt's last design, Steppenwolf, was built for Dave Fowler as a bare hull. Much to Alan's chagrin the boat was not well finished and despite a promising first season (Almost winning the Silver Tiller) it was quickly sold into obscurity and no-one else thought the concept worth pursuing.

Vintage boats.

The boats listed in this section are most likely to be seen racing at clubs on reservoirs inland. None are less than 35 years old, and although they form the backbone of the class, they are unlikely to have been further afield than the local circuits, where they still have their day, especially if equipped with a modern rig.

They make an excellent, low cost, introduction to the class. Prices start at around £500, though many potential restoration projects go for much less.

If you are looking to buy or have bought a boat in this section you will be interested in the age adjusted handicaps. The MROA have published a set of PY ajustments which you can find here.


Both Gregory designs were radical departures from established design principles. Each was quite unlike anything that had gone before. The Ghost Rider is one of the most successful designs of the seventies.

Ghost Rider (1970)

Very stable, excellent boats for lightweights, especially in heavy weather. Slow to tack, so not ideal for river sailing, and perhaps reluctant to plane in marginal conditions. V-sectioned with less rocker forward than earlier designs. Beam 6'10" (2.09m), and suitable for up to 22 stone. There are some modified versions of this design. Ghost Riders won the Silver Tiller in 1972 and 1976, the Inlands in 1973 and 1976, and the Nationals at Plymouth in 1971. Other Championship results include 5th 1970, 6th 1971, 2nd 1972 and 6th 1973. The design aged well and remained around the pace foir much longer than many of its contempories. Nowadays they are only really suitable for sailing off an age adjusted handicap or against boats of their peer group. But in that role they remain - in good condition - a very good introduction to Merlin sailing for lighter teams. Beware of bodged modernisation attempts.

Echo (1973)

Round-sectioned development of the Ghost Rider with full, shallow entry, and narrow rounded transom. On smooth water, this design shares the characteristics of Ghost Rider but slams badly to windward against a short chop and is therefore not a good sea boat. A full bow is not usually associated with nose-diving tendencies, but in the case of the Echo, the extra resistance when the nose goes down apparently makes the boat difficult to control in strong winds, especially in waves.


These early Keith Callaghan designs are at their best on restricted water. Keith's philosophy was that upwind performance was vital to get away from the start at sea and from other boats inland. Their reputation for needing careful handling downwind is perhaps only partially justified.

The early designs, especially Hotspur, have a high initial stability, which can lull the inexperienced into a false sense of security on the run. A wave, a windshift or carelessness in bearing off can cause a death roll before the helm wakes up. Apart from this possibility, the early designs are quite easy to sail.

From Hexagon on, Keith's designs became less susceptible to the death roll. However, they have less initial stability, which means that more precise handling is required if they are to win races.

All Keith's popular designs were fast boats in their time, and very rewarding to sail. All except Hebron and perhaps Hazard, are responsive and quick-tacking in light airs. Hotspur and Hornblower were built by a wide range of amateur and professional builders. Many are excellent, but beware of poor construction.

Hebron 1966

Very stable and good in a blow, but sluggish in light airs. The first Merlin to reach a beam of 6'6" (1.98m). Only one was built. Suitable for less than 20 stone.

Hotspur 1968

Development of Hebron, with finer ends. Excellent river boat. Beam 6'3" to 6'5". Suitable for about 23 stone.

Hornblower (1970)

Designed as a maximum beam development of Hotspur, with narrower waterlines. The original Hornblower was wider than boats subsequently built to the same underwater shape. Good in a blow, slow in light airs. Beam 6'9" (2.06m) except the prototype. Suitable for up to about 23 stone. 4th in the 1972 Championships and 2nd in the 1972 Silver Tiller.

Fourunner (1973)

An experimental 4-plank Hornblower. The only 4-plank construction Merlin Rocket, requested as an experiment by the class committee. It did not take on.

Hexagon (1973)

Development of the Hornblower for improved light weather performance. Very fast in expert hands. Beam 6'10" (2.08m). There is a maximum beam variant which is also very fast (e.g. 4th in the 1973 Inlands) but which is said to be difficult to handle offwind. Hexagon is suitable for up to about 24 stone. Winner of the Silver Tiller in 1973 and 1974, and second in 1973, and second and third in the 1974 Championships. Quick tacking and could still be a fast river hull in waiting.

Hysteria (1974)

Development of the Hexagon with reduced keel rocker aft, and softer bilges. Very fast all round, in expert hands, with a further improvement in offwind handling. Suitable for up to 24 stone. 4th and 6th in the 1974 Championships and 6th in 1975. Callaghan's best - many built by Aln Boatyard. As with Hexagon this could become a good design for river sailing.

Hazard (1977)

Development of Hysteria, with reduced keel rocker and more U-section bows. Good in a breeze, but not such a good weight-carrier in light airs. Suitable for up to 22 stone.


Rob Inglis took advantage of the technology available in the Naval Architecture Department at University College London. For his second design, Bad Company, he made use of computer visualisation facilities. These enabled him to assess the effects of design changes and crew position on wetted area and stability of the boat in a range of heel and trim states.

Still well worth a look on restricted water, but totally outclassed offwind by the newer designs.

Risk (1974)

This boat has a very fine U-section bow merging into a rounded mid-section with a slightly V'd run. There is very little keel rocker forward and the centre of buoyancy is well aft. Risk proved to be very stable and good in a blow, but slow tacking and disappointing in light airs. Beam 6'9" (2.09m).

Bad Company (1977)

A fine V-section bow blends into a rounded mid-section and narrower waterline aft. The shape is somewhat distorted at mid length in order to keep the waterline narrow whilst just satisfying the rise-of-floor measurement. Keel rocker is low. Beam 7'0" (2.13m). Good inland, excellent to windward and carries weight, but hard work in a blow.

Bad Company is suitable for crews up to 28 stone. It is average in both tacking speed and stability. This design won more open meetings than any other in 1979. However, the design won a race at the Championships at Falmouth and finished 7th overall. Won the Silver Tiller in 1979 and '81, 2nd in 1980.

Still well worth a look on restricted water, especially later versions with a low bow tank. Excellent upwind but offwind it lacks planing speed, a problem that has not improved as things have moved on!


Since building his first two designs for himself, Guy Winder has become one of the leading builders of the Merlin Rocket class. Guy's background as an aircraft engineer show in his quest for precision in building. His designs can be recognised by their characteristic convex sheerline and relatively narrow transoms, although these features are less marked on his later designs. His home waters at Hollingworth Lake made him lean towards boats which would perform well on lakes.

These boats accelerate quickly and some helmsmen have unexpectedly slid downhill along the sidedeck and over the transom into the water! Their crews report that this is somewhat disconcerting. Recently Guy and son David have concentrated on building boats to variations on the Canterbury Tales shape (see the modern section earlier on in this document).

Wideguy (1973)

Based on the September Girl design and modified for a beam of 7'0" (2.13m). Extreme convex sheer. This boat proved to be very fast carrying about 20 stone.

Late Night Extra (1974)

This boat differs from Wideguy in having a finer entry, less wetted area, and the centre of buoyancy further aft. The chine is more pronounced and the transom deepened slightly but reduced in width. This boat finished 5th in the Inlands twice in 1974 and 1975. Beam 7'1".

Winderbox (1975)

Development of Late Night Extra with increased beam aft, deeper hull and stem, and the chine reduced again. Beam 7'1". Very fast in all conditions in expert hands, but difficult to sail well. Suitable for up to 23 stone. There are several variants of this design. One early example won a Championship race at Abersoch in 1978 and seemed to be heading for a place in the first three, but failed to complete the required five races. Winner of the Silver Tiller in 1978, 6th in the Inland Championships in 1976 and 2nd in 1978.

Clasher (1977)

U-sectioned development of the Winderbox for improved sea performance and increased weight carrying ability. Beam increased at the shrouds and reduced aft. Stem deepened and chine softened. Beam 7'0", suitable for 21-24 stone. Three were built, 3114, 3132 and 3139.

Disguys (1978)

Further development of Clasher for increased weight carrying ability. Several variants of this design have been built with differing hull depth and beam, and different transom widths. Beam between 6'10" and 7'1". An example of this design won a race in the 1979 Championships at Falmouth and another finished 3rd overall. This design won the Inlands that year and is suitable for light to medium weights.

Stilleto Mark 1 (1980)

This arrowhead-shaped hull was designed to be heeled when sailed upwind and was intended to sail in the direction of the chine from the leeward corner of the transom to the bow. A gybing centreboard was designed-in to align the intended direction of travel. Although Stiletto achieved a few good results it was not the success hoped for. One of the major problems was the amount of wetted area around the transom especially when at sea and this impaired good all-round performance.

Stilleto Mark 3

On two occasions Guy took out the transom and cut darts into the hull, pulling the planks together to reduce the wetted area. He also altered the bow for a finer entry. The gybing centreboard was abandoned and Guy now considers Stilleto's performance to be acceptable for lightweight crews. The boat has had several successes and Guy actually won the last race of the 1984 Championships in this boat.

U-turn (1982)

This is a development of Disguys, with increased beam aft and with the bows made finer above the waterline. The way in which the hull is planked has been revised accentuating the U-section entry. Does well at Oulton Broad.

Uptown Girl (1984)

This design is a modification of the Phil Morrison NSM 2, flared out to maximum beam with a wider transom, flatter rocker and fuller at the ends. Designed to carry more weight, the boat proved very successful with 27 stone on board.

Modified Uptown Girl (1985)

Same as the above but with a narrower waterline for lighter crews.


September (1969)

Phil's own first Merlin - home built.

September Girl (1970) & Phantom Kipper (1972)

Derived from Phil's very successful China Doll design of a National 12. In their day a quick tacking, very good all-rounder for medium weights  but they were better inland than on the sea. Beam 6'4" (1.93m) and 6'9" (2.06m) Suitable for 24 stone. Phantom Kipper is simply a widened September Girl and shared the same underwater shape. It was very popular in the north with many built at the Aln Boatyard. Both of these designs were sought after in their day, but now need to be raced in their peer group or off an age adjusted handicap for best enjoyment. They could still exceed themselves on restricted water in light winds and a properly set up modern rig on a sterengthened hull has potential for river sailing.

Satisfaction (1972)

Designed for good light weather performance carrying heavyweights. This design achieved its purpose admirably and is an excellent choice for heavyweight crews, especially inland on the river. Said to be hard work to windward when sailed by lightweights. Beam 6'3" (1.9m). Suitable for about 26 stone.

Smokers Satisfaction and Fadeaway (1974)

The Smokers Satisfaction is a flared-out version of the previously successful Satisfaction, designed to carry more weight. This design is probably the most famous all-rounder and certainly one of the most successful designs ever. It has proved successful at all levels with a variety of crew weights, and aged very well with good results well after its time. A variant of this design is the Fadeaway.

It is noted for being a good all rounder, and is a reasonably fast tacker, so still a good choiucve for small lakes or the river. It is good in light airs and was certainly the most successful design of the late seventies. It won the Championships in 1975, 1977 and 1980, and won the Inlands in 1974 and 1977 (Fadeaway won in 1974). Its populariuty saw many attempts at strengthening and updating examples of this design with varying levels of success. 

A very popular design in the mid-late 70s 101 of these boats were built by a number of builders, both professional and amateur. The variations produced by differing interpretations of the drawings vary from the conventional to bizzare!

Infidel (1974) & Hooligan (1975)

In it’s time a very good open water boat for lightweights. Extremely stable, but very slow tacking, and thought to be unsuitable for restricted water. Beam 6'10" (2.09m). Suitable for under 20 stone (Infidel) and up to 22 stone (Hooligan).

Several varieties of this design exist, with improved weight carrying ability and light weight performance, merging into the Hooligan design but this was still rather slow tacking and sluggish in light winds, though it would carry weight better. The best known variant is the W.T. Special Infidel which finished 4th & 5th in the 1974 championships, 5th in 1975 and 10th in 1979.

This design suffers from there being more Ghost Riders and Summer Wines around, both of which do what these boats do better within their peer group. For age adjusted handicap racing it will prove a competant design within the limits explained above.

Mustard Seed & Super Seed (1976) 

An experiment with a 'gull wing' underwater shape for reduced waterline beam and low wetted area, Super Seed had more more curve in the bilge to carry more weight. Had the occasional open meeting success and the two built by Bill Twine both had good records at championships but neither design caught on.

Summer Wine (1977)

This design was an extreme one in its day. With a fine U-section bow and flat aft sections it is very fast reaching in strong winds but has been noted for its nose-diving tendencies when hit by a sudden gust (sit on the transom or sink!).

This design was initially popular and then went out of fashion when the NSM2 came along. Then in the early eighties it had a big revival, especially with lighter weight crews.

NSM1 (1978)

This design was in concept somewhere between the Smokers Satisfaction and the Summer Wine. Essentially the Smokers was well known for its ability to carry weight, and the Summer Wine was a design for lightweights. The Wine's classy performance caused the well-built fraternity to pester Phil Morrison for a Wine that would carry weight. NSM stands for “New Smoking Material”.

This boat was an instant success when introduced in 1978, and soon became the most popular design, particularly after the GRP version appeared in 1980, some 35 being built. The NSM2 derivative quickly replaced it in the early eighties and it must be said too, that the rig was evolving rapidly at this time, and since 1980 boats have had a low bow tank which gives more hull stiffness to cope with the increasing loads placed upon it by the modern rigs.

The NSM's stability makes it suitable for those regularly racing in strong winds or those converting from more stable boats such as GP14's who find other Merlin designs a bit tippy. These days its a bit of a design in limbo, thought to lack the quick tackling necessary to make it a desirable river or small lake boat but also lacking the outright planing speeds necesary for open water. In reality this could make a good example a bargain for the future, especially off an age adjusted handicap.

NSM2 (1980)

The NSM2 used to be the design most people think of as a first Merlin for someone sailing inland. The design is a development of the NSM1 with fuller sections under the mast and in the bilge near the stern to carry more weight (around 24-26 stone).

There are also two variants: Guy Winder modified the design to produce Uptown Girl (3338) which was filled out even more under the mast to carry more weight, and Jon Turner has produced a Seventh Heaven version which is slightly wider, has a slightly flatter rocker and a slightly flatter transom. Quite a few have been built in FRP, though the wooden ones tend to be preferred, especially examples by Winder, Rowsell’s and Jon Turner.

The NSM 2 can be summed up as an extremely good all rounder. It was still in production in GRP long after it was percieved to be outclassed for championship sailing and if looking to sail off an age adjusted handicap you will need to get thisntaken into account if you buy a 35xx numbered boat.

The GRP "Wembley One Designs" are NSM IIs built from a mould taken from Seventh Heaven, a very successful boat built by Jon Turner. They  were largely supplied by The Welsh Harp Boat Centre and were built by several builders. They were quite popular within Wembley SC where the NSM II remained competetive through the 1990s and into the noughies. The rigs they were supplied with evolved over time, the very last examples being supplied with carbon rigs. Their fit out is optimised for inland sailing and while equipped with raking rings they are not able to be set up like the modern boats and its exceedingly difficult to improve this cost effectively. They're a good low maintenace first Merlin, but don't buy one thinking its a Winder mk 1!

Gnome and New Potato

The Gnome is definitely a boat for the lightweights, excellent in it’s day on open water - preferably a sea with a moderate chop. It is a development of the New Potato and is a real flyer on the reaches. Only two New Potatoes have been built, but it won the Silver Tiller in 1984, was second in the 1982 Championships, and 3rd in 1983. However, while the flatter hull planes faster, it does make the boat less versatile than the NSMs which are perhaps better across all conditions. The history of the design can be traced back to the Summer Wine and indeed the rocker is exactly the same. Relatively few have been built, but again in the right hands and with a modern rig it could still be fast at ST meetings on open water, but early CT designs will have the necessary equipment as standard and do it better. Nowadays these are better suited to club racing off an age adjusted handicap.

NSM3 (1983)

An NSM2 variant designed to carry a little more weight with slightly increased rocker in the run, and slightly fuller sections from the mast to the transom. Only two boats have been built to the design 3327 & 3340. Black Adder came 2nd in the 1983 Championships.

NSM4 (1984)

A popular design in the late 1980's, this boat is a development of the NSM family and has moved the NSM concept closer to the Summer Wine. This means that the boat is very flat, quick to plane, very wide to give extra power and is aimed at an all-up weight of around 22-24 stones. The design is basically an NSM2 flared out above the waterline, with slightly flatter forward underwater sections. There are many examples of NSM4s on the water. The minor variations produced by builder's tolerances and interpretations are alleged to significantly influence performance.

What is a White Whale?

This is an NSM4 built by Rowsell and Morrison which has spray-painted decks and insides, instead of the usual varnish. The subsequent reduction in man-hours required to finish the boat have enabled this version of the NSM4 to be produced more cheaply than a conventional Merlin. Although these boats were successful on the water only four were built, owners preferring to pay a bit more for a beautiful wood finish.

Design 42 (1990)

Underwater sections are closest to the NSM2, whilst above the water the greater sitting-out power of the NSM4 is retained. The design name apparently comes from The Hitch Hikers Guide to the Galaxy! Deep Thought and Roaring Forties have been built to this design.


Ian Holt started his Merlin design process with a clean sheet and an open mind. His very early boats are a little unconventional, but most were still fast. Relatively few of these boats have been built, and they tended to be specific either to Ian himself or the client who ordered it.

Most of these boats havent been seen for many years and if you buy one the class stalwarts will be interested!

Nice Legs

Rudely described as a cross between a Ford Sierra and an aircraft carrier, this boat was a complete break from the current fashions in the fleet. Very full in the bow, high freeboard and a huge foredeck created by having the maximum beam well forward where the crew sits, finished off with a bustle in the run aft. All this had the rest of the fleet scratching their heads in disbelief. This was not helped by having a large radiused traveller on the foredeck for a self-tacking jib. Initially slow, the boat became gradually faster throughout its life and had a good championship at Whitstable in 1989 in the hands of its builder, Guy Winder, six years after its launch. Like most of Ian's designs, it did better in strong winds.

Once Bitten

The lessons learnt with Nice Legs resulted in Once Bitten, at the time the most extreme hull shape being built. Characteristic of Ian's designs have been the very flat forefoot, a hard shoulder just above the waterline near the midships section, and a chine in the run aft. These were retained, but reduced slightly compared to the original design, and the bustle significantly reduced in the run aft. Sold within a few months of being built to Alan Warren, this boat came 6th, 3rd and 3rd again in the 1986, '87 and '89 Nationals respectively.

Diamond Smiles

There have been two near sister-ships to Once Bitten, both taken off the same frames. The first is Diamond Smiles, designed over a telephone conversation between Norway and Bradford, when Ian Holt was working over-seas. The only differences between Once Bitten and Diamond Smiles are an increase in the rocker both just behind the bow section and in front of the transom, in an attempt to carry weight slightly more successfully. This boat finished 6th overall at the 1985 Championship and won a race at the Championship in 1987 - the first Holt design to do so and the first sign of a threat to the Morrison monopoly.


Holt was convinced that he still had not found the solution to the heavyweight's problem, and further development 1989 led to a new design for 1990. Based on Canterbury Tales, this design has a fuller stern and slightly deeper midships section. Built by Ron Hall for Sue Aubrey – hardly a heavyweight – the boat was sold quite soon after being built and was not seen on the circuit regularly afterwards. 


Dangerbat was commissioned by Dick Batt for 1987, having watched the performances of Once Bitten and Diamond Smiles in the previous seasons. Dick wanted to take the design concept to its logical extreme and went to Guy Winder with a number of modifications. The most significant was to straighten out the run aft to eliminate any hint of a bustle. Another move, more obvious but of less significance, was to incorporate a rounded transom, removing some weight in the stern of the boat. This boat, after being sailed with slightly too much weight on board for its first season, finished tenth at the 1988 Nationals before winning the championship in 1989, proving devastatingly fast both upwind and down with the correct crew weight on board. Definitely not a boat for heavyweights!

Riders on the Storm

Riders on the Storm was the first boat to be commissioned from Holt, and was a result of discussions at the 1985 Championship when a heavyweights' answer to the NSM4 was being sought. It was further development of the Once Bitten/Diamond Smiles concept, but an attempt to find more buoyancy somewhere in the underwater sections without losing what was considered to be an extremely fast and powerful planing hull design.

Who's a Pretty Boy

Simultaneous to the design work being carried out on Riders, a South-East version of this idea was being put together with Alan Jackson, aimed at the pond sailor and Salcombe Week. This design won a race at Salcombe, but thereafter never received the time and effort to assess the potential of the boat. The changes were basically to tuck in the transom to help tacking and carry heavier helmsmen. Soon on the heels of WAPB - in fact off the same frames - came Heap Big Rudder, so named because the designer’s last notes to the builder were to stick a very large rudder on the back of all these boats (having watched Warren capsize countless times in Once Bitten during the windy 1985 Championship). This was simply WAPB with the transom dropped half an inch to reduce the bustle at the rear end. This lengthens the waterline for speed in sub-planing winds but needs a lighter helmsman.

Riders on the Storm 2

Otherwise known as Buckle Up, this was a modified version of ROTS1, incorporating the owners' ideas for the next season. On the water for 1988, this boat is possibly the best of the Holt breed for the heavyweights, and won the Silver Tiller in 1988. This was followed up with second place at the Inlands in 1989, 4th overall at the '89 Nationals, and another overall victory in the Silver Tiller. Guy Winder and Ron Hall built the few examples ordered, they should still compete with a Canterbury Tales if armed with a decent rig, but this is hard to substantiate as none have been seen on the circuit for a long time.


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