RC boat - What is the best Propulsion system?

[gibtron02]

Hello, I am working on a custom RC boat (battery powered). It is a catamaran style (2 hulls) and it is being built to carry a maximum load of 60lbs at 7mph. Based on the hull design it has been determined that the total drag force to overcome is 8.50 lbs (per hull). So I know I need a propulsion system that can give me greater than that. This is where I'm having a very difficult time determining what the best means of propulsion for my boat should be!!

I've looked into using propellors in a channel, jet drives using both a centrifugel pump and axial impeller style pump. I have no experience with this sort of thing and could use some serious advise!! Thanks in advance!!

[Boston]

if you google propcalc you should find an application that will determine the HP needed and the prop for a given hull form