Right Motor Driver
We used a low internal resistance Maxon Motor for the right and left motors.  We drove the motors only in one direction off of 14V so we did not need an H-Bridge.  We built our own simple motor drive circuit using an IRLZ34N and a diode.    
Left Motor Driver
Bilge Pump Circuit
We drove the 12 V bilge pump off of 14 V(only for a short period of time). We used the same circuitry as the right and left motor drivers.  We connected the bilge pump to an IRLZ34N for High Side drive.  We added flyback diodes to protect the transistor.
Motor Drivers & Pump Circuitry