Which do you think is the most successful Merlin Rocket design ever? 

If longevity were an important attribute I suggest it would be the three 'Passing Clouds' built by Jack Holt. 'Passing Cloud' no. 1079 was built for my late father Harry Harris in 1960 as was 'Flinkidink' no. 1097. 'Fair Kop' no. 1212 was built in 1961. All three race and sometimes win at Tamesis as does the glass version 'Luka' no. 3560.

'Passing Cloud' has been winning races for the Harris family throughout her life. As recently as last year my nephew Richard with Jason Stokes won the Cookham open meeting in her. She's 50 next year and deserves a big party to celebrate the pleasure she's given to so many people for half a century.

If longevity is an important attribute then the original Merlin design is surely the best as shown by Iska no.6 now sporting a 25ft rig at Baltic Wharf last Saturday. Also Terrapin no 36 which has sood up well to some testing conditions in the last few years and of course there's Garry's Secret Water no 111.

Picture of Iska linked below

Not to take anything away from the 'Cloud' boats, but has much design work been done on river boats since the 70s? (Yup, I am completely ignorant.)

Numerically it has to be Smoker's Satisfaction and NSM2, both of which are still excellent river boats.  In terms of design dominance it's the Canterbury Tales as it has brought development of other designs to a standstill though the basic shape has been tweaked a bit.

I do wonder just how stable the Passsing Cloud design is as it always seems to rock about such a lot in light winds.

Really?!!!

Rule 42!!

Smokers are the lovliest in light winds, EZroller is the best rush on a reach.Ever.

Let it Ride beats EZ downwind (if you keep the nose up). Owned both, know.  Still rather sail EZ Roller overall if tacking on ponds/rivers is an issue (where do you think the name comes from?)  Dan Alsop and others have proved competitive longevity of Let it Ride design.  Statistically NSM2 must be a runner given spread of build dates (1980 through to late 90's with plastic revivals) or maybe Canterbury Tales is beating it now for longest fashionable time range 20yrs still going but can all the variants count as the aame design?

The obvious choice would be the Canterbury Tales + clones, as it is demonstrably the pinnacle of Merlin evolution to date, therefore has to be the most successful (survival of the fittest etc). But my vote would go to Phil's Smokers Satisfaction, because of the numbers built, the time span of its dominance, and the range of its successes in all wind strengths with a (moderately) wide range of crew weights.
Robert, the Passing Cloud is truly a classic Merlin, but with only 4 built can it be eligible for the top slot?
Mags, as far as I know, there has been zero development of river boat designs in the last 40 years. I have some ideas which could be developed into a new design if anyone has £20k spare. I'm sure that Laurie would jump at building it.

I agree with Keith, there has been no hull development of boats specifically for river sailing since a group of Jack Holt boats built in 1962/3. Indeed the only river boat built in recent years is 'Luka'no. 3560 which is a fibreglass copy of 'Passing Cloud'. The most important development on many of the vintage boats is carbon rigs and Kevlar sails. Also 'Passing Cloud' and others now have spinnaker chutes.

Keith my answer to your question is that three wooden 'Passing Clouds' were built 49 years ago, all of them plus 'Luka' will probably be racing tomorrow.

Robert, you have a point. What Merlin design of any vintage can claim to have a 100% turnout on any day? I am a great admirer of Jack Holt and his dinghy designs: although I have designed several boats in then 5.5m to 7m range, the boat I currently own and sail is a Yachting World Rambler, built in 1954, and, you guessed it, designed by Jack Holt.

The comment above is not exactly correct as both Luka and Flinkydink are owned by the same person and even he is unable to sail two boats at once.  

Also Luka is not made of fibreglass, it is made of wood...

I've talked to brother John and he confirms that 'Luka' is built of wood.

After talking to John I've realised that I've dropped another clanger because I've always thought only three origional 'Passing Clouds' were built. In fact another five were built - 'Bali-Hai no. 1268, 'Kingpin no. 1279, 'Halloa' no.1280, Amarylis II no.1282 and 'Tyste no. 1294.

If anyone has knowledge or information about these boats please let me know.

If it's the ability to still win certain meetings / races 50 years after it was built then I guess the Passing Cloud design is currently in a league of it's own. 
However I suspect there are several other "pimped" vintage boats that could go as well in the right hands(not you ITK though), although they are all only competitive in restricted waters in light to medium winds.
Passing Cloud is coming to Salcombe again this year so hoping for light winds and long beats against the tide.....

Plus 1242 Farida making 7 by Holt and the more mosern one = 8.

Actually, ten by Jack Holt and all registered over a two year period 1960/61...
1079 Passing Cloud
1097 Flinkidink
1141 Stratus
1212 Fair Kop
1242 Farida
1268 Bali-Hai
1279 Kingpin
1280 Halloa
1282 Amarylis II
1294 Tyste

Well done whoever you are. You've obviously got better eyesight and more patience than me!

So, where are they all then?

I'm not David Vines....!!

I believe my nephew Richard will be sailing 'Passing Cloud' at Salcombe. 

If you want to challenge 'Passing Cloud' in her favourite environment go to the CRSC  Silver Tiller meeting on the 17th May where they will be defending the trophy they won easily last year.

Mr H,I believe Bali-Hai was at Earlswood until the late 80,s ,Jon Wood who owns pocket rocket now might be able to ask a few members if its still about,I think his no is in the yearbook.