boatraising

Boatraising is the maritime salvage procedure of bringing a vessel that has sunk, run aground, or settled in mud or shallow water back to the surface or to an afloat position. The goal can be to repair and return the vessel to service, or to salvage it for parts and prevent environmental damage.

Common techniques include:

- Inflation of pneumatic lift bags or placement of flotation pontoons to provide buoyancy around or beneath the hull.

- Use of cranes, heavy-lift vessels, or travel lifts to lift the vessel once buoyancy is sufficient.

- Controlled dewatering and pumping to reduce weight and stabilize trim during the lift.

- Patchwork and temporary repairs to allow refloat or movement.

A typical operation proceeds as follows: a preliminary assessment of hull condition, buoyancy, currents, and seabed is conducted; the area is secured to prevent pollution and protect personnel; lifting points and attachment methods are planned; flotation devices and lifting gear are deployed; the lift is initiated with careful control while dewatering progresses; once afloat, the vessel is secured to a barge or tug and moved to a repair yard or suitable location.

Equipment and considerations include buoyant devices (air bags or pontoons), lifting slings and cranes, dewatering pumps, ballast control, and divers for inspection and attachment work. Environmental and safety concerns emphasize spill prevention, fuel/oil containment, and adherence to applicable maritime salvage laws. Depending on jurisdiction and insurance, salvage rights and compensation structures, such as General Average, may apply.