Question: gearbox for boats

Hello to all out there.My name is rikus veuger,original from holland but now  living in bandung,indonesia.

I also want to build my own wooden boat and I am looking for many information by reading books and looking on the net.

But some questions I cant seem to get an answere for.So I try out here on this group.

 

It is maybe silly to ask but I am just curious to know why in a boat there is not a automatic gearbox.I ask this becouse I want to build a speedboat and I know that it take a lot of power to speed up the boat until it has

a surtain speed and start to get in plane.

Then you can lower the rpm of the engine but keep the speed.I thougt by using a gearbox the rpm can lower again,saving fuel and give more comfort.

 

My other question is about the angle of the shaft of the propellor.If the shaft and engine are on a angle it seems to me that, becouse of the direction of propellor power, the nose of the boat is lifted and the back is more down into the water.What is the use of that?

Is it not better to use a horizontal propellor,like a saildrive.It will give much more efficienty and it will be more pleasant to sit in when at lower speed becouse the boat stay horizontal. 

 

I hope some one can give me some clear answere to one of my ,probebly silly,questions.

 

All the best

 

Rikus Veuger

 

By the way.I am a trader in East Indian Rosewood,so if anybody needs some timber I can help you to get this great wood,almost any size or quantity.