Dedicated section
http://www.rcuniverse.com/forum/rc-airboats-246/

get a watt meter they are cheap and you can read the current drawn at full revs ( although its not moving) this will give you an idea as to the run time of your battery and the capability of your ESC to handle the load. I think every one who uses electric motors and especially lipo batteries should have one!

It's really a case of suck it and see .Experiment is my mantra for stuff like this.Just try it and see what the results are. You could ask the aero bods on say Aeromodeller or RCME ( Flying Models ) forums of a number of others.👍

if your using electric power its a case of matching rpm to watts. it is quite normal to use 3 bladed prop of the same diameter and pitch as a 2 bladed prop on the same model.

The increase of blade area results in increased thrust with an obvious increase in current used.

So for any given system its a case of matching motor revs/current/battery life to the motor parameters.