Best settings for direct into wind

We see from this video that this boat can progress directly windward driven by the wind. but how to calculate the correct settings and gearing between the wind-turbine and water prop?

 

I wouldn't consider gearing on the driveshaft, you would add weight and friction.
But as for the rest???? A lot of trial and error I suspect is the only way. So many variables, such a random operating environment.
Are you the original builder?

 

First estimate your boat specs, then determine the most efficient wind turbine (controlable pitch for different wind speeds) which lets you determine the rpm and torque you get from this specific turbine, then search for the best fitting propeller for your boat, with the deliverd rpm and torque from the windturbine. If necessary use a gear (will likely be that you need it).
There will be some iterations necessary do determine a well working, efficient design.
Don't forget that the wind turbine will produce angular moments which effect your boat's stability etc.

 

It's as designing a normal boat with the extra component wind turbine which is your powersource. Proper design and a good understanding of the output of the wind turbine are crucial for this kind of boat.

 

Direct shaft drive is very good idea as you can see, for you can scale both turbine and prop and be done with that. Hovever on boat with any sort of practicality you will have to have option to go in any direction angle to the wind. There still be at least 1 90degrees joint on your shaft. You could use something like Voight schneider propeller, but that is mechanically complex device which would benefit from some simplification - like to have fixed vectoring to the aft, for this purpose. Vertical windmill would be also better as you wouldnt need to turn it into the wind, wind from any direction would turn it, but they tend to have bad efficiency.

 

I am not the builder of this model you can find information about these craft on www.sailwings.net/rotaryhome.html