I research rip currents where Cosby Show star Malcolm-Jamal Warner drowned. Here’s why they’re so deadly

Malcolm-Jamal Warner, the actor who played Theo Huxtable on The Cosby Show, has drowned on Costa Rica’s Caribbean coast.

It is reported that he was swimming at Playa Cocles in Limon province when a current pulled him offshore. This is a beach popular among surfers and one that’s known to have large waves and strong currents.

It’s also a beach that I have taken students to in order to study the formation of rip currents and to better understand what beach users know about the hazard.

What exactly are rip currents?

Rip currents—commonly referred to as rips or colloquially as rip tides—are found on ocean beaches and some large lakes around the world.

The rips at Playa Cocles and along a large part of the Costa Rican Caribbean coast are known as channel or bathymetric rips that form as the nearshore sand bar moves toward the land through the summer. The water thrown towards the land by the breaking waves returns offshore as a concentrated and fast flowing current at gaps in the nearshore sand bar.

During storm conditions, we have measured the rip currents at Playa Cocles at over two meters per second. These rips are known to increase rapidly (or pulse) in strength due to changes in wave breaking, leading to unsuspecting swimmers being taken far offshore and exiting beyond the zone of breaking waves.

While it can be difficult to spot a rip from shore, they can be identified by an area of relatively calm water between breaking waves, a patch of darker water or the offshore flow of water, sediment and debris.

Caught in a rip current

A person caught in a rip is transported away from shore into deeper waters, but they aren’t pulled under the water. If they are a weak swimmer or try to fight the current, they may panic and fail to find a way out of the rip and back to shore. Survivor stories highlight panic, anxiety, distress and fear, a tendency to fight the current and an inability to make a decision on how to escape the rip.

While it is possible to “break the grip of the rip” by swimming parallel to the beach or toward breaking waves at an angle to the beach, there is no single escape strategy due to the unique rip circulation pattern.

It’s possible to escape a rip by flipping onto your back, floating to keep your head above the water and following the current until you’re returned to the shore by the current or able to swim safely toward the shore. If you are taken beyond where the waves break, or you’re unable to swim back to shore, continue to float and signal for help.

Rip currents account for more than 50 deaths a year in Costa Rica; approximately 19 drownings a year involve foreign tourists from the United States, Nicaragua, Canada and Germany. While most drownings in the country occur on Pacific coast beaches that are a short distance to the city of San José, more than five drownings occur each year along the Caribbean coast.

Playa Cocles was the site of five drownings that occurred over eight days in 2004, an event that prompted tourism-dependent business owners to establish a lifeguard station on the beach.

Costa Rican drownings

On average, each drowning in Costa Rica costs more than US$2 million (USD). This includes the direct costs of search and rescue, the costs of repatriation and the long-term economic burden of a lost life. This is in addition to the great personal loss experienced by family and friends.

A survey at Playa Cocles and other beaches in Costa Rica revealed that a majority of beach users did not observe warning signs and that many were unable to interpret the warning and did not change their behavior.

The majority of foreign drowning victims in Costa Rica had limited knowledge of rips and were unable to avoid the times and locations that were most hazardous.

In general, visitors to a beach often use simple visual cues when deciding to take risks. Recent studies suggest that tourists think beach access points and resorts are located adjacent to safe swimming areas, particularly when visual cues such as manicured paths and promotional posters that promote swimming at those locations.

Visitors are a high-risk group for drownings. They’re generally unfamiliar with the beach and its safety measures and often have poor knowledge of beach hazards, such as rip currents and breaking waves. This lack of knowledge can be exacerbated by language barriers, an overconfidence in swimming ability and peer pressure.

Playa Cocles is a beautiful beach, but it’s known to have dangerous rips depending on the size of the breaking waves and the position of the sand bar.

When visiting any beach—from the Caribbean to the Great Lakes—it’s important to remember that there may be rip currents and to take serious precautions.

This article is republished from The Conversation under a Creative Commons license. Read the original article.