1. Department of Marine Technology, Norwegian University of Science and Technology (NTNU), Trondheim NO-7491, Norway e-mail:
2. Department of Marine Technology, Centre for Autonomous Marine Operations and Systems (AMOS), Norwegian University of Science and Technology (NTNU), Trondheim NO-7491, Norway e-mail:
3. Department of Marine Technology, Centre for Autonomous Marine Operations and Systems (AMOS), Norwegian University of Science and Technology (NTNU), Trondheim NO-7491, Norway;
4. CNR-INSEAN, The Italian Model Basin, Rome 00128, Italy e-mail: