Rip current

A narrow, fast channel of water flowing away from shore through the surf zone, a hazard for shore divers and swimmers entering or exiting the water.

A rip current is a narrow band of water flowing seaward through the surf zone, formed when waves pile water against the beach and it escapes back out through a gap in a sandbar or reef. Rips can run faster than 2 m/s, quicker than anyone can swim, and they are a real hazard during shore dive entries and exits rather than at depth.

The classic mistake is trying to swim straight back to the beach against the flow. The correct response is to swim parallel to shore until you leave the narrow channel, then angle back in with the waves. For a diver in full gear the same rule applies, and you also have the option of dropping below the surface turbulence, since rips are strongest at the surface.

Divers can sometimes use a rip deliberately as a free ride out through the surf zone, but only at familiar sites and with a clear exit plan. Learn to spot rips from shore: a gap in the breaking waves, churned sandy water, or foam moving steadily seaward. Local lifeguards and dive shops know where the regular rips form, so ask before your first entry at an unfamiliar beach.