This is my RC airboat ( It's still in progress, it has no rudder and has to have the supports glued on the base, a foam kick board). The motor support is Lego with a wood motor mount glued on .
Step 1: Mount and Flotation
The supports are Lego bricks, girders, and pins. the mount is wood with four computer screws it's glued using plastic safe glue, it will be glued onto a kick board for flotation
Step 2: Electronics
For a battery I used a large lithium battery it's blue. The motor and ESC where off an old airplane that crashed, so was the servo and receiver. The motor is a black brushless motor attached to a silver spindle with a grey 10 by 9 propeller.
Step 3: Steering Mechanism.
The rudder is made from plastic sign board, The servo is on the top of the boat.
A piece of music wire connects the servo to the rudder. The rudder is attached with cloths hanger wire.