Understanding Currents Will Save Your Life

When I first started snorkeling off Corona del Mar beach I was accidentally caught up in a wave; it crashed me into rocks clad in barnacles, and these suckers have sharp outsides. I was able to scramble out onto the stones between waves, but blood was coming from numerous cuts on my chest and belly because of the sharp barnacles. This taught me to stay away from barnacles, that’s why I kept trying to swim away from the pier. People walking on the dock thirty feet above me noticed my lack of progress and began yelling advice.

Oh! I finally realized the plan, the people on the pier want me to go right through, that's what they were telling me, I realized. I still didn’t want to go between the sharp barnacle-clad pilings, but the chanting above, and the inability of the boat to get closer to me caused me to make up my mind.

More people came to the railing edge, and they started screaming too. I needed to concentrate on my swimming, so I blocked out their noise. Soon a patrol boat was maneuvering to assist me, but it too was getting too close to the pilings. A lifeguard in the skiff yelled through a megaphone to swim through the pilings.

I picked a spot as best I could and swam right through the pilings. Soon it was over, and the crowd dispersed.

A rip current (sometimes incorrectly referred to as a rip tide) is a strong, narrow, fast-flowing current directed toward the sea that travels up to one to two meters per second. Rip currents usually develop close to the shoreline in very shallow water around a meter deep - just where beach bathers are usually found.

For rip currents to form, there must be areas close to the beach where some waves break and other areas where they do not. Usually this is caused by sandbars on the seabed that form from the sediment deposited by waves and tides. Waves are encouraged to break when traveling through the shallower water over the sandbars, but they don't break when traveling through the regions of deeper water between them.