Survival craft, particularly lifeboats and liferafts, are highly buoyant and can move considerably in rough seas. Although they are designed to withstand severe weather, careful handling is essential to prevent capsizing and to improve the comfort and safety of the occupants.

In heavy weather conditions, it is often safer to allow the lifeboat to ride the waves by keeping its bow facing into the wind and sea or slightly off the bow. This is achieved by deploying a sea anchor, also known as a drogue, from the bow of the survival craft.

The sea anchor acts as an underwater drag device that helps maintain the correct heading of the lifeboat while reducing excessive drifting and preventing the craft from turning broadside to the waves.

If the engine of the lifeboat fails, deploying the sea anchor becomes especially important. Without it, the boat may turn sideways to the waves, causing severe rolling and increasing the risk of capsizing. By maintaining the bow towards the approaching waves, the sea anchor greatly improves the stability and safety of the survival craft.

Many lifeboats also carry a supply of wave oil, usually consisting of light vegetable, fish, or animal oil. When released in small quantities onto the sea surface ahead of the lifeboat, the oil helps reduce the breaking action of waves, making sea conditions less severe around the survival craft.

Once the sea anchor has been deployed, the oil bag can be attached to its hawser using a buoyant heaving line passed through the thimble located at the end of the hawser. This arrangement allows the oil bag to be replenished whenever necessary while continuously spreading oil ahead of the lifeboat to smooth the approaching waves.

When weather conditions improve or the sea anchor is no longer required, it can be recovered by pulling its tripping line. This action empties the water from the sea anchor, reducing its resistance and making recovery much easier.