As opposed to the 540 motors, i have used a set of 800 sized motors with excellent results. the torque is amazing and are really efficient. I also run gear reductions off the motors aswell. The gear reduction will allow for more efficient power. My first plan of attack is usually find the most scale correct propeller and work backwards to the motor gearing. A quick bit of math will find your proper gear ratio with the motor voltage, RPM, propeller operating range, and the planned speed for the model.

as a hint, I am piecing together power for a new project. Twin 800 motors, (aprox 18000RPMs@12v) 5.0:1 reductions with 3 1/2" 5 blade props. The hull LOA is 75" with a 23 beam, I am expecting it to weigh in at close to 100lbs when ready to run. I will have removable ballast. this is not a boat I am looking to break any speed records, its a full displacement pleasure boat.

Tom