This report describes the first engineering trials dives of the new UK 6500m-rated ROV Isis during Voyage 7, Leg XXX of the RV Atlantis, 6-13 March 2003. Mobilisation occurred in Jacksonville, Florida, following a period of refit for the ship between March 2-5 and first FAT (factory-acceptance) testing was achieved on March 7 during transit from Florida to the Bahamas in ca. 850m of water. Upon arrival in Bahamian waters, a swath bathymetric survey was conducted of the northeast Providence Channel immediately west of northernmost Eleuthra Island where a tongue of >4000m-deep ocean intrudes among the shelter of the Bahamas Islands. Three further dives of the ROV were conducted in this area between March 8 and 11, 2003, to depths of, respectively, >2000m, >4000m and >1000m. The first two of these dives proved the extensive depth capability of the new ROV and provided first opportunity for the UK ROV team to work with the vehicle. The third dive in Bahamian waters allowed imaging of the local seafloor fauna and collection of sample material with the manipulator arms - important for proving the capability of the vehicle for demonstration to both the scientific community and the wider public in the UK following significant Government investment. Because of insurmountable bow-thruster problems aboard ship, however, dive operations had to be abandoned early on March 11 and could not be recommenced pending further dry-dock maintenance. To that end, the cruise was ended ahead of schedule with the scientific party disembarking in Nassau, Bahamas, by pilot boat on Wednesday, March 12. Despite this disappointing end to the cruise, three important objectives were achieved:
1) Preliminary FAT testing demonstrated the viability of the core system for the ROV.
2) Dives to >2000m were achieved (max >4300m) with up to 7 hours on the seafloor.
3) Basic seafloor imaging and sampling capabilities were demonstrated and documented.
Christopher R German (Southampton Oceanography Centre)
North Atlantic Ocean
northeast Providence Channel
Geology and geophysics
Quantity: number of dives = 4 Description: Imagery of seafloor collected during testing of ROV Isis
Quantity: number of surveys = 3 Description: Swath bathymetric surveys