Aquatic Accidents: Expert witness consulting by Ph.D. Scientists

Rip Current Safety

How rip currents work, why they are dangerous and how to be safe.

Rip Current Glossary

Rip Current Anatomy - Most rip currents have a “neck” and a “head” that is often defined by an unusual disturbance or choppiness in the water and by murky discoloration caused by sand and debris. As a result of the current’s speed, sand is forced into suspension often causing a rip current to be associated with “dirty” water.  Sometimes a rip current will lose its characteristic mushroom shape when strong long shore currents deflect a rip in its prevailing direction.

Beach- accumulation of wave-deposited, loose sediment, usually sand, that extends from the outermost breakers to the landward limit of wave and swash action.

Breaker- a wave that has become so steep that the crest of the wave topples forward, moving faster than the main body of the wave.

Ephemeral Rip Current- a rip current which quickly forms and quickly dissipates; often called a “flash” rip.

Feeder- the currents that flow parallel to shore before converging and forming the neck of a rip current.

Flotsam- debris in the ocean water.

Head- the part of a rip current circulation typically located beyond the breakers, marked by a spreading out or fanning of the circulation. It is here where the velocity and strength of the rip current circulation begins to weaken considerably.

Jetty- on open seacoasts, built structures extending into a body of water to direct and confine the stream or tidal flow to a selected channel, or to prevent shoaling. They stabilize an inlet by intercepting the longshore transport of sand that would otherwise fill it in or cause the channel to shift position. Jetties are often confused with groins, but are much longer and more substantial structures, usually built in pairs.

Permanent Rip Current- a rip current usually associated with a manmade object, such as a pier or jetty, and sometimes with naturally occurring geological features, such as a channel in a coral reef.

Rip Current- strong, localized current flowing seaward from the shore; visible as an agitated band of water, which is the return movement of water piled up on the shore by incoming waves.  Rip currents are by far the biggest killers of ocean swimmers. Rip currents form as waves disperse along the beach causing water to become trapped between the beach and a sandbar or other underwater feature. The water converges into a narrow, river-like channel moving away from the shore at high speed.

Rip Tide - a distinctly separate type of current includes both ebb and flood tidal currents that are caused by egress and ingress of the tide through the inlets and the mouths of estuaries, embayments and harbors. These types of currents may cause drowning deaths, but these tidal currents or jets are a separate and distinct phenomenon.

Sandbar-  an offshore ridge or mound that is submerged (at least at high tide), especially at the mouth of a river or estuary, or lying parallel to, and at a short distance from the beach.

Temporary Rip Current- a rip current that is the most common and may form on any beach.  It is usually short lived, but can be very dangerous.  Some temporary rip currents migrated down the beach in the direction of the long shore current, while other are ephemeral.

Undertow- general layman's term used to describe coastal currents which may “suck” swimmers underwater.  A more accurate description is backwash, which occurs from large breaking waves or seaward-flowing rip currents.


Stephen Leatherman