Carry out non-destructive testing such as tests for cracks on the legs of oil rigs at sea.
Check and maintain diving equipment such as helmets, masks, air tanks, harnesses and gauges.
Communicate with workers on the surface while underwater, using signal lines or telephones.
Cut and weld steel, using underwater welding equipment, jigs, and supports.
Descend into water with the aid of diver helpers, using scuba gear or diving suits.
Inspect and test docks, ships, bouyage systems, plant intakes and outflows, and underwater pipelines, cables, and sewers, using closed circuit television, still photography, and testing equipment.
Install pilings or footings for piers and bridges.
Install, inspect, clean, and repair piping and valves.
Remove obstructions from strainers and marine railway or launching ways, using pneumatic and power hand tools.
Repair ships, bridge foundations, and other structures below the water line, using caulk, bolts, and hand tools.
Salvage wrecked ships and/or their cargo, using pneumatic power velocity and hydraulic tools, and explosive charges when necessary.