| 1. | Communicate with workers on the surface while underwater, using signal lines or telephones. |
| 2. | Take appropriate safety precautions, such as monitoring dive lengths and depths, and registering with authorities before diving expeditions begin. |
| 3. | Check and maintain diving equipment such as helmets, masks, air tanks, harnesses and gauges. |
| 4. | Descend into water with the aid of diver helpers, using scuba gear or diving suits. |
| 5. | Obtain information about diving tasks and environmental conditions. |
| 6. | 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. |
| 7. | Repair ships, bridge foundations, and other structures below the water line, using caulk, bolts, and hand tools. |
| 8. | Cut and weld steel, using underwater welding equipment, jigs, and supports. |
| 9. | Recover objects by placing rigging around sunken objects, hooking rigging to crane lines, and operating winches, derricks, or cranes to raise objects. |
| 10. | Install pilings or footings for piers and bridges. |
| 11. | Take test samples and photographs to assess the condition of vessels and structures. |
| 12. | Install, inspect, clean, and repair piping and valves. |
| 13. | Operate underwater video, sonar, recording, and related equipment to investigate underwater structures or marine life. |
| 14. | Remove obstructions from strainers and marine railway or launching ways, using pneumatic and power hand tools. |
| 15. | Salvage wrecked ships and/or their cargo, using pneumatic power velocity and hydraulic tools, and explosive charges when necessary. |
| 16. | Set or guide placement of pilings and sandbags to provide support for structures such as docks, bridges, cofferdams, and platforms. |
| 17. | Perform activities related to underwater search and rescue, salvage, recovery, and cleanup operations. |
| 18. | Supervise and train other divers, including hobby divers. |
| 19. | Carry out non-destructive testing such as tests for cracks on the legs of oil rigs at sea. |
| 20. | Drill holes in rock, and rig explosives for underwater demolitions. |
| 21. | Remove rubbish and pollution from the sea. |
| 22. | Perform offshore oil and gas exploration and extraction duties such as conducting underwater surveys and repairing and maintaining drilling rigs and platforms. |
| 23. | Cultivate and harvest marine species, and perform routine work on fish farms. |
| 24. | Set up dive sites for recreational instruction. |