Things You'll Need
Instructions
Attach the trapezoidal plates to either end of the 4-peg x 12-peg plate. Four pegs should be attached to the underside (make sure the plates are centered), with two pegs sticking out. Repeat this process for the other end with the second plate.
Attach the single LEGO brick to the double LEGO brick.
Attach the double LEGO brick to the center end of one of the trapezoidal plates to simulate a fin.