1) Offshore drilling descriptor 
[technology] Subsea is a term to refer to equipment, technology, and methods employed in marine biology, undersea geology, offshore oil and gas developments, underwater mining, and offshore wind power industries. Remotely Operated Vehicles (ROVs) are robotic pieces of equipment operated from afar to perform tasks on the sea floor. ROVs are ...
occurring, working, etc., under the sea or ocean: a subsea specialist in oil rigs.