Take appropriate safety precautions, such as monitoring dive lengths and depths and registering with authorities before diving expeditions begin.
Check and maintain diving equipment, such as helmets, masks, air tanks, harnesses, or gauges.
Communicate with workers on the surface while underwater, using signal lines or telephones.
Descend into water with the aid of diver helpers, using scuba gear or diving suits.
Obtain information about diving tasks and environmental conditions.
Supervise or train other divers, including hobby divers.
Inspect the condition of underwater steel or wood structures.
Inspect and test docks, ships, buoyage systems, plant intakes or outflows, or underwater pipelines, cables, or sewers, using closed circuit television, still photography, and testing equipment.
Repair ships, bridge foundations, or other structures below the water line, using caulk, bolts, and hand tools.
Recover objects by placing rigging around sunken objects, hooking rigging to crane lines, and operating winches, derricks, or cranes to raise objects.