We have designed two boats which we will compete in the lightweight, heavyweight and long distance races of the 2017 Hydrocontest. The aim of the contest is to develop new ideas for commercial shipping, increase public awareness of maritime issues, and to inspire the next generation or maritime engineers. The lightweight boat will carry 20 kilos around a circuit and the heavyweight boat will carry 200 kilos. For the long distance race, the lightweight boat will complete as many laps as possible around a different circuit within a certain time limit. The hydrofoils on the lightweight design are swept back, providing better passive stability, and the long, thin monohull will improve previous handling issues. The rudder will provide better handling than previous directional thrust systems, and its leading edge will counteract and use the rotational flow generated from the propeller. The propeller is facing forward to produce a smooth water flow that will improve the propulsive force. The two thin hulls of the heavyweight’s Small Waterplane Area Twin Hull (SWATH) design further minimise the hull drag, so increasing the vessel’s overall efficiency. Two torpedoes under each hull provide extra buoyancy and lift. A ballast system keeps the boat stable and at a safe depth in the water by pumping out more water as the weights are loaded. An active control system will be connected to the centrally articulated hydrofoil, causing the boat to roll in the opposite direction to the waves, increasing stability during the race.