According to the United States Lifesaving Association it is a powerful narrow channelized current of water that moves directly away from the ocean shore. They commonly form in sandbars, piers, and jetties. They can quickly drag people and debris away from the shore.
Rip currents pull swimmers away from the shoreline and push them into the deeper ocean. They are powerful and fast moving and account for a significant number of ocean lifeguard rescues.
Before entering the water look for narrow gaps of discolored water. Often times there will be seaweed or debris that clump together on the surface of the water. Look for a break in the wave pattern, where waves look calmer compared to the rest of the breaking waves in the water.
Remain calm. Remember rip currents will not pull you underwater, only away from the shore. Panicking will only exert your energy. Try treading water to give yourself time to assess the situation. Start to swim parallel to the shoreline and once you feel the pull lessen shift yourself towards the shore. Let the crashing waves push you closer to the shore and continue to watch them to be aware of the break line.
Always swim near a lifeguard. Make sure that you are in the protected area that the lifeguards are surveying. Be aware of the flag color for the water, they highlight the level of risk. The flags are often located near or on the lifeguard stand. Look for other signs that could indicate the swimming area and other risks.