DISCOVRE 2008

Cruise Log: 10/09/2008    

Dry Side ROV Operations

Amanda W.J. Demopoulos

Examining the deep sea using ROVs or submersibles requires a well orchestrated team that operates behind the scenes. For our cruise, the ROV team is made up of a pilot, Matthew Cook, co-pilot, Geoff Cook, and surveyor, Jeff Snyder. In order for the operation to go smoothly, each team member has a specific function, but they are also well trained in the other jobs, allowing them to substitute for each other as needed. Deploying the ROV requires a host of personnel, including a winch operator to raise and lower the ROV and garage and deck hands to guide the ROV into the water and to manage the tether system (umbilicus attaching the ROV to the garage and ship). Once the ROV is in the water, it is controlled on deck inside a container equipped with a variety of gear, including multiple monitors and other communication devices. This container is home to the ROV team and scientists as they sit, observe, and record dive operations for several hours. Using his controls, the pilot parks the ROV in the garage for the descent, and together they are lowered to the sea floor. While the ROV descends through the water column, the pilot and the Bridge of the ship are in constant communication so that they can coordinate placement of the ROV on the seafloor. As the ROV and garage approach the seafloor, the pilot reverses the ROV out of the garage to take a look around and select a site to set the garage on the bottom. The seafloor in this region can be very rugged and contain numerous carbonate blocks; there are few flat areas available for the garage to sit on, thus selection of a garage placement site can take some time. After the garage is secure on the seafloor, the team prepares to sample and conduct transects. For sample collections, Matthew maneuvers the ROV into position while Geoff prepares the manipulator arm to do collections. Meanwhile, Jeff Snyder pays constant attention to the position of the ROV and garage, relative to the ship, and records the locations of our sampling collections. If the pilot or co-pilot needs a break, Jeff is available to step in and take over as needed. After collections are complete and the ROV is ready to be recovered, it parks in the garage once again for the ascent to the surface. Recovery of the ROV is much like the deployment, and requires close coordination of maneuvers to get it back on deck. Once the ROV is secure on deck, scientists collect the samples from the bioboxes and sediment cores and the ROV team retrieves data and makes repairs as needed. The ROV is then put to bed until another day.

ROV at the surface, ready to descend to the first station. - (photo credit: USGS DISCOVRE Expedition) - click to enlarge

Inside the container, pilot, Matthew Cook (left), directs the ROV on the seafloor while he watches real-time video on the large screen monitor. Geoff Cook (right), co-pilot, prepares to maneuver the manipulator arm for sample collections. The top screens include information on the ROV position and direction, digital still camera views, and position of the ROV relative to the ship (far right screen). - (photo credit: USGS DISCOVRE Expedition) - click to enlarge

Geoff Cook makes some adjustments to the ROV after the dive is completed. - (photo credit: USGS DISCOVRE Expedition) - click to enlarge

Jeff Snyder gathers data from the ROV after a dive. - (photo credit: USGS DISCOVRE Expedition) - click to enlarge