Catamaran wing sail idea

Revise your ideas about monster outboards, as most sailing cats will be limited in speed, compaired to what a set of big outboards can produce. Size them appropriately, but don't get carried away with thinking much bigger is better, because all you'll do is beat the water to a froth, with little return on the investment, except with your fuel bill.

 

I actually second that, think David's client wants that power, and the linked thread is about David's struggle to find a way to make some use of it.

Hence the ‘‘Er... what?’’ emoticon at end of the line in my previous post.

(hold the cursor on the emoticon to see the text)​

 

Sailing performance is all about achieving a high lift/drag ratio for both the aerodynamics and the hydrodynamics. The problem with a power cat is the hull drag is already high. So no matter how efficient the rig is, the boat is not going to sail very fast or point very well into the wind, and will probably not go to windward at all without a daggerboard. So when you run out of fuel, your options may be very limited. And even dangerous if you are trying to stay away from a lee shore. Another issue is power cats have a narrower beam than sailing cats, so they are less able to stand up to the heeling moments produced by a sail rig. This greatly increases the chances of capsize, and it is another limit to the power you can get from the rig.

When you're under power, the apparent wind will be coming so much from ahead that the wingsail will not be able to contribute much in way of auxiliary power, either.

A better option than a wingsail might be a kitesail. It won't take you to windward, either, but it can be stored away in a bag and trotted out as emergency propulsion if you have engine failure. Limited options may be a lot more attractive than no options in that situation.

 

Zero Emission Catamaran pulled by a Dragon kite across the Atlantic​

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Mile-High Mega Kites Could Pull Giant, Floating Power Plants​

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The below quote comes from the first link in the above post...

Does anyone know what ‘‘a high-seasight’’ means in this regard . . ?

P.S. - Oh well, on second thought, I'll guess it means a ship or a boat that has seen the high seas . .

BTW, - ‘‘first time in the history of shipping’’ - ‘‘only with a wind-solar drive’’ - to keep the first sentence true, then don't cut ‘‘solar’’ out of that sentence . .