George,
Please be a bit cautious when reading that Rob White article about his version of the Atkins Rescue Minor. There have been questions raised about his figures and how close his boat was to the original Atkins plan.
The Atkins boat was designed to be a big water rescue craft with a tunnel to protect the prop.
The White version was inspired by the original but not exactly the same. Apparently one of the draw-backs was that it was not easy to turn. Tunnel hulls have very complex hydrodynamics - to raise a column of water up 8 inches costs power and increases the draft required. If you use less than 20 hp, the boat will not act the same.
One of my questions on that design is if it needs the full 20 hp to get on to plane. And then, once on plane, how much power is required to maintain that plane.
If I were building a boat designed for electric,
- For monohull - use a design stolen from a fairly wide sailing dingy with a shape designed to eliminate the "hump" transition from displacement to planing speed.
- For twin hulls, long narrow catamaran hulls.
- For tri-hulls, a wave piercing style - (one of John Holtrop's maybe).
>>From: George
>>I'm thinking of the same thing and looking at Atkins Rescue Minor design. It was featured in Woodenboat mag, March/April 2006 no.189 and July/august 2010 no.215. This version had 20 hp diesel and did 29 nautical mph at 20 knots so the hull looks pretty efficient. % to 10 hp electric should make it go pretty well.
>>George
>>George
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