Update

We are not using a pulley to pull up the walls, instead we're going to make a gate attached to the tank using hinges, and can open like a gate to let the boat through. We cut out two pieces of the plastic glass to make the gates.

We used plastic glass to make the tank instead of using wood or finding a tank. It was A LOT OF WORK.

We need something to seal the open space beside and under the gate so that the water doesn't leak into the other sector unintentionally.
                                    
                                ~Jisu