Planing Catamaran!

[HelmutSheina]

Yes I think the SP80 crew made an announcement on Facebook that they may continue their tests and potential record runs from Walvis bay in Namibia. though last year they reached close to the record... 15kts to go as average to match.

It's an excellent site and the country itself spectacular to visit but the I imagine French guys will have more infrastructure at home to fabricate and make modifications/repairs. Not that it's relevant but the seawater in namibia has a year round particulate yellowish olive hue to it which seems more opaque than most ocean water I've encountered. Walvis Bay supports a big fishing fleet and there is a seal colony at the end of the sandspit at Pelican point but the locals in 2012 told me the WhiteSharks have not discovered it yet so a popular activity is kayaking amongst the seals and kite boarding in the bay.
140hp. Yeah I have an old haines 1600S with OMC140. Excellent ride quality in rough water with steep deep V but maxes out about 90km/hr. Prop set up for skiing rather than max speed.

Congratulations, 40 Kn on an ironing board, i'd have said "pull the other one", but you supplied the video. Would you mind if tried this on sailing cat hulls please?

 

[Greg Mc]

Interesting . It's like mini hydro hull . Probably hydro hull is faster than cat on flat.

Yup exactly hydro style Step hull can maintain ideal planing trim angle. We started making these in early 1980s after the Catamaran was confiscated . I rode a larger version of the Yellow board seen here for 35 years and never once had anyone that could match pace let alone overtake it, and that with an ancient bombora wave sail.

 

[Greg Mc]

Congratulations, 40 Kn on an ironing board, i'd have said "pull the other one", but you supplied the video. Would you mind if tried this on sailing cat hulls please?

We did try this on planing cat hulls. Have a look a few post pages back . ( or did you mean are you asking if you can try it?) It's an idea over 100 years old and fair game to anyone legally but I do notice some Americans have tried to patent step hull speed boats as if it's some new innovation and not something every seaplane hull or hydroplane has used since the 1920s. I have this other patent idea for a mode of transport for a ground contact device that is topologically a single surface that orbits radially around a lubricated point equidistant from the transitory point of ground contact....cough.. In Australia we do have design registration which gives a degree of protection from a direct copy of a design rather than an idea but what is allowable in USA as a patent is absolutely absurd. By that measure what I designed in my Industrial Design course in the early 80s for every project would bankrupt Mutinationals like Apple. The step hull cat seemed insanely fast based on my water skiing and speedboat and sailboarding experience as comparison but never precisely measured, with the disadvantage of being slower than a thin displacement cat in low wind speeds under 7 knots, but in winds around 10 knots and above they can plane and the step helps them plane at an optimum trim angle (though we tried modifications to deal with swell. http://www.gregmckee.com/Wet and Wild Fluid Dynamics.htm
I notice some people take the attitude that "if this kind of craft is so fast how come they don't win all the (...) Class course races" which is rather like saying "if top fuel dragsters are so fast how come they have never won Le mans?" "If sailrocket is so fast how come it has never won the sydney to hobart?" We were at the time alway interested in outright top speed rather than course racing and like most of our sailboarding friends had no interest in triangular courses but more of a Defi Wind straight line speed course approach which just maximised adrenalin and we thought with some development we could make a production boat that could potentially break the outright world sailing speed record at the time. In 1982, the absolute world speed sailing record over 500 metres was about 36knots and didn't seem that insurmountable a challenge