106 stations including CTD, UWTV, Shippek and Anchor Dredge taken on board the RV Celtic Voyager in August 2013. A large instrument package called a CTD is the standard workhorse of oceanographers for acquiring water column profiles. It is called a CTD because as a minimum it measures electrical Conductivity, Temperature, and Depth (pressure). The plankton net is a funnel-shaped, fine-meshed net that is towed through the water. The net concentrates the plankton from hundreds of gallons of water that pass through it. A simple net can be constructed to capture microscopic plankton. A remotely operated vehicle (ROV) is an unoccupied underwater robot that is connected to a ship by a series of cables. These cables transmit command and control signals between the operator and the ROV, allowing remote navigation of the vehicle.