The biggest challenge was to design the vehicle in such a manner that it would float, and in such a manner that none of the essential electrical components (the engine and the solar panel) would get wet. We created a "roof" for the boat-car, on which the solar panel rested, and surrounded the main "floor" with a border to prevent water from getting in. We also hot-glued ping-pong balls to the sides for extra buoyancy. Unfortunately, the axles for our wheels could only fit on the underside of our boat, meaning we had to cut out a section of the bottom for the gear attached to the engines to be able to connect to the gear on the axle of our wheel-propellors. This ended up being a huge design flaw that caused our vehicle to fail as a boat due to water getting in through the hole. Due to bad lighting on the day of the race, we powered our boat-car using a battery instead.