I'm a noob, so this may not be relevant to your boat. I had really good luck with this motor.
1. 20" long 5lb DICKIE tugboat, travels at from zero to 10 mph for 5hrs+ on one 7.2Volt 2A nimh battery.
The prop is the stock boat prop, direct drive. Even though your boat is almost 60" long, this motor, or two of them, might be good for you.
2. Vac-U-Tow Towboat motor, direct drive
3. Aquacraft 15A ESC, one 2A NiMh battery.
http://www.modelboatmayhem.co.uk/forum/index.php?board=125.0http://www.vac-u-boat.com/Motor545.htm again i apologize if this is not relevant to your boat,
all the best,
weeds
Additional info (Admin):Vac-U-Boat's 545 type DC motor for direct-drive installation in scale boats.
TW103 (bare motor) and TW104 (motor with leads and caps installed).
This is a new DC 545 type motor manufactured by Johnson Motor Company for Vac-U-Boat. This is the standard Vac-U-Tow Towboat motor. 0.125" diameter x 0.53" long smooth shaft. 1.4" diameter x 2.85" long overall. No load speed of 3,100 RPM at 7.45 volts. No load amp draw of 0.22 amps at 7.45 volts. At stall, 2.54 amps at 7.45 volts. Designed for 13.8 volt automotive use, it can handle 6-volt and 12-volt gel cells.
Epoxy-computer-balanced 5-pole armature has 75 turns of 0.27mm copper wire. Higher low-speed torque and lower RPM than 3-pole stock motors. Large bronze oil impregnated bushings. Carbon brushes. One internal capacitor on the negative terminal. This motor can direct-drive a 1.75" scale prop with cool-quiet performance.