Self-propelled crafts intended for underwater operations that may or may not be independent of surface support, (ABS).
- Remotely operated vehicles (ROVs) – Cable-controlled underwater vehicles used for underwater inspection, repair and maintenance. Long before the drilling rig support, ROVs were used to dig trenches and cover transocean communication cables.
- Autonomus underwater vehicles (AUVs) – Novel subsea fully autonomous vehicles built for deepwater commercial survey works such as site surveys and pipeline route studies.
The C&C Technologies HUGIN 3000 is 5.2m long, 0.96m diameter with a depth rating of 3000m. It is powered by a unique aluminium oxygen fuel cell developed to give the vehicle an endurance of 40 hours.The normal speed is four knots. Survey systems include a Simrad EM2000 multibeam and bathymetry system, EdgeTech chirp sidescan sonar, EdgeTech chirp 2-16kHz subbottom profiler, Seabird CTD and a magnetometer.