Props size..help!

[david]

I'm fitting out a 40" hull, 6lb / 3kg boat at the moment. It's a very old
hull I have renovated and was, at the time (c1940) a speed boat. I have
addedd a deck to make it look like an old air sea rescue boat.

I intend to fit a speed 700 with Robbe 35mm prop, direct drive on cells from
8 -10 depending on trial and error.

On inspection the prop seems small when compared with the hull. Does it
seem too small for such a vessel?

D

[Kris Flynn]

i dont know much about these things...but yeah it sounds small :)

For such a big hull i would consider a gearbox.

Kris

[Tachikaze]

Can you send a picture of the boat and the prop. It would be helpful to see what you have in hull configuration.
We run boats much larger than 47" on props that are about 1 3/4" to 2 1/4" diameter.
How much speed are you looking to obtain? Is this a planning hull?
Not enough information to be too much help.
Do not gear this! Gearing will only decrease you drive time. We can get this up to speed with direct drive with the right motor/prop/battery combination.:D