Marine drives consist of gearboxes, couplings Couplings Couplings are used to connect two shafts for the transmission of torque, and to compensate for misalignment or movement. , and auxiliary systems specially designed for maritime applications. They are built to withstand continuous operation and must meet requirements such as corrosion protection, noise reduction and high reliability. Different configurations may be required depending on the type of ship and area of application. Examples are merchant ships, naval vessels or research vessels.