One of the interesting things about the Merlin is that on GPS plots etc a fully powered up Merlin is actually doing more than 5.2kts to windward without ostensibly planing - the transition from displacement to planing is very gradual with no obvious hump in the speed curve.  Downwind in flat water you would be doing well to exceed 15kts I reckon.  Anyone in this technological age got anything to prove otherwise?

Someone asked me today how fast a Merlin can go?

... I do mean on the water, and not being towed by a speedboat etc.

Depends which Merlin Rocket and who is sailing her!!

There's probably a calculable sub planning speed based on waterline length and a notional crew weight, but I've no idea what aerodynamic limitations there might be once over planing speed - perhaps its infinite...... Maybe its easier to establish how fast anyone has ever gone in a Merlin - should lead to a few tall stories!

28.9302010018282 mph

We recorded David Winder at 15 knots at Rutland a couple of Opens ago.  Measured by Rib speedo.

my old boat could do 88mph

I got my first speeding ticket doing 105 mph crossing the Tay Bridge, only caught as I had to stop at the toll booth! 1976    and then 37 years of undetected crime until the other day. Off to naughty school next week instead of 3 points though.

I believe that Lionel Mendoza of Wembley holds the Merlin land speed record from London to Sheffield.

Once got into a speed wobble with a Hurricane 5.9 on the back (24 ft. rig). Car, Turbo Technics Capri. Lethal combination and so dragged the wobble out past all the freight and was well over XXX when I looked at the speedo (Porsche none turbo eater). Alternative was a messy jack knife. Believe it the fastest a Cat has ever gone on the road. Well the rest of the fleet thought so at the time.

Thanks Steve, that was exactly the kind of answer I was looking for.

I would have thought the honour of fastest on the road must go to Robin Judah who before my days was summonsed for exceeding the then 30mph trailing speed limit. In court Robins evidence was that he had not been followed or stopped. The policeman's evidence (He rode a big fast motorcycle!)"I was doing the maximum my machine would allow and the accused was still drawing away" Robin paid up and bought a Jack Holt Roof Rack for his Aston Martin!

Over about 14 years I crewed Robin in Firelies, his ancient leaky Hornet no. 298, his oddball MK VII Merlin Rocket, 'Mint Julep' no. 599 and his first Soling. I never once travelled to these events with Robin so I can't corroborate David's story about his speeding. However I remember the astonishment when he first arrived at an open meeting with his boat on the roof of his Aston Martin. He used a Jaguar to tow the Soling around Europe.

It's amazing to think that when I started towing boats the speed limit was 30 mph as mentioned by David. If you were towing with a van it was 20 mph! Barry Perry, who later won the Burton Trophy, was prosecuted for towing his Nat 12 with a van at more than 20 mph on the way home from a Scarborough Burton Week!

I think if you do the equation with waterline length etc (memory fails me)it comes out at slightly over 15 knts...

Theoretical maximum 'displacement' (i.e. non-planing) speed of a MR is about 5.2 knots, but I know of no formula to calculate maximum planing speed. I guess that it is down to power/weight ratio, the sea conditions and the ability of the crew. 15 knots would be my guess for a maximum.

Ha ha ha

Alan Warren and Christ Andrews were towing their Flying Dutchmen in convoy back from Poole with Alan ahead. It was a lovely day and the traffic was quite heavy. Alan decided to drive at twenty miles an hour and surprisingly the traffic ahead cleared. We drove from Fareham to Arundel and never saw a car ahead of us. A few cars did overtake us and waved at us. We waved back even though we didn't know who they were. Once a funeral director always a funeral director!