Make the casualty buoyant on the surface

Having reached the relative safety of the surface, it is important that the casualty does not accidentally re-descend. The usual methods of making the diver positively buoyant are to:

• inflate the buoyancy compensator. This is a routine surfacing drill in some training schemes.
• inflate the drysuit, if one is being worn. The gas in a dry suit is not very secure; it can easily escape from seals and vents. Also, excess gas in the suit tends to make the legs buoyant causing the diver mobility problems.
• drop weights.

Divers who are out of air will probably not be able to inflate their buoyancy compensator or drysuit using the normal and simple technique of pressing the direct feed injection valve. If their equipment allows it, they may be able to inflate these devices orally or use an integrated gas cylinder (if fitted).