 Within these through-hull tunnels, several propellers appropriately sized for the vessel they’re installed on, are housed.Depending on the size of the motors driving these propellers, they could draw an insignificant amount of power or a large amount of power that requires much caution to operate.Another smaller subset of positioning thrusters is those used for maneuvering unmanned aquatic vehicles like Guanay II AUV tested by scientists from Spain (Masmitja, 2018).