The development of the CLIPPER autonomous underwater vehicle (AUV) is a joint research project (JRP) between DGA/BEC in France and FFI in Norway. The power source is a semi-fuel cell using oxygen dissolved in seawater as oxidant, seawater as electrolyte and magnesium as fuel. Predicted range for the vehicle is in excess of 1600 nautical miles at a speed of 2 m/s. Design depth is 600 m. This long endurance, as well as the large internal volume of 7401 of the pressure hull, makes the CLIPPER vehicle an excellent tool for long range subsea operations. (C) 2004 Elsevier B.V. All rights reserved.