In article , "D MacPherson"
writes:

The answer to that question depends on the application - type of propeller,
power loading, operating speeds. Can you tell us a little more?

I'm playing with the base design for a hydrofoiling semi-wing-in-surface-effect
craft; electric, solar-electric, hybrid-electric; semi-kayak-ish main hull with
proa-like outriggers. The motors (probably Minn Kota but haven't ruled out
using more efficient motors used in electric vehicle competitions) will be
located at the base of either V-type wave-piercing or T-type fully submerged
foils, so part of my current task (and the basis for my admitedly
vague/nebulous question) is to make sure that the props stay at a functional
depth as the foils rise. Current design allows me to vary the depths of the
foil-prop assemblies. I'll ask the question again after I've figured out how
light I can safely make the frame/hull, how many batteries I can pack and still
stay safely buoyant, which will finally lead me to foil, motor and prop
choices.

Warm Regards
Shawn