Marine salvage is the process of rescuing a ship, its cargo, or other property from peril. Salvage encompasses emergency support for saving sinking vessel, rescue towing, refloating a sunken or grounded vessel, or patching or repairing a ship. The oil pollutants, hydrocarbons or other contaminants are biggest environmental hazard. The recovery of these pollutants from sunken vessel is often considered a high priority.

Offshore diving is the most well known branch of commercial diving, with divers working in support of the exploration and production sector of the oil and gas industry. The work in this area of the industry typically revolves around the maintenance of oil platforms, building of underwater structures used in the production process, installation, NDT survey, UWILD survey, inspection & survey with CCTV, general inspection, etc.

Onshore diving is the work often being in support of land based civil engineering projects, with the majority of the work either underwater survey or construction work. The number of dive sites and divers can be found working in harbours and / or sheltered waters. Dredgers can be used to maintain, expand and deepen areas that have progressively become shallow from deposits (silt, mud, sand, etc.).

As the name suggests 'Hydro' underwater diving services are required on contract basis on Hydro power plants/ dams. Penstocks for hydroelectric installations are normally equipped with a gate system and a surge tank. Flow is regulated by turbine operation and is nil when turbines are not in service.