The ocean can be a source of beauty and serenity as well as a volatile and dangerous beast. When exploring any maritime environment, it is important to acknowledge the power of the water and be informed as possible regarding safety precautions. In a nearshore beach environment, the biggest threat of danger looms in rip currents that sit offshore. Rip currents, in the right conditions, can be life-threatening, and statistically they are the proximate cause of 80% of rescues carried out by beach lifeguards.
The following guide is written to provide a comprehensive view on how rip currents are generated and how swimmers can guard themselves against the dangers posed by rips.
WHAT CREATES FETCH?
The majority of energy on Earth stems from the sun, presented as both heat and light. As the Earth spins on its axis, this causes an unequal distribution of energy; this regulates into what are commonly known as pressure systems.
These high and low pressure systems are constantly seeking to balance into equilibrium – this transfer of energy often results in turbulent weather conditions and is the reason why one can expect inclement weather whenever a ‘front is coming through.’ One type of weather phenomena generated by this energy transfer is wind.
When wind blows over a large body of water for an extended period of time, the energy transfers into the water and generates fetch, which will continue along its course until it reaches shore.
WHAT CREATES SURF?
Waves are formed when the energy generated from fetch hits a shallow point on the ocean floor. This energy will cause the water to rise into a breaking wave.
The bathymetry of where the wave is breaking will greatly impact the shape of the wave and the dynamics of the nearshore environment in general; as the ocean floor has entirely different compositions depending on location, no two beaches are exactly the same.
For example, waves breaking in Hawai’i will be entirely different than the waves in Outer Banks; in the former, they break primarily over coral reef, whereas the latter enjoy the gentle sand bottom of a beach break.
WHAT CREATES RIP CURRENTS?
Rip currents are generated by moving water fueled by breaking waves needing a location to recede. As a fluid with low viscosity, water will simply “go with the flow” and move into space – this is the basic premise of a rip current.
Looking out from the beach onto the prospective ocean floor, one might guess that the bathymetry remains relatively constant, and that the beach remains a gently rolling slope down into greater depths.
This view is a little misguided – in reality, the surface of the ocean floor is just as dynamic and eclectic as its counterpart on land. There are ridges, and divots; in-shore holes and crevasses; sandbars and wide gaps that pepper the coastline.
Rip currents are essentially formed when the water from waves recedes in a deep spot between two shallow areas. This will form a surface current that will ebb away from the shoreline – depending on the strength of the current, these can range from barely noticeable to life-threatening.
WHAT DO I DO IF I'M CAUGHT IN A RIP CURRENT?
The single most important thing you can do if caught in a rip current is to not panic. Panicking, or struggling to swim against the current, will only tire yourself out and make yourself more susceptible to exhaustion. In water that is too deep to stand in, this is incredibly dangerous and is what influences most drownings caused by rips.
Instead, remain calm and “go with the flow”. Remember from the earlier sections how rips are formed – the current will not propel you out far into the open ocean; rather, as soon as the current passes the breaking point of the waves, it will completely dissipate into the open water.
If you have carried a floating item into the water with you, you can simply float on top; otherwise, relax and float on your back. If you have the swimming ability, you can try and swim sideways out of the rip.
CALLING FOR HELP
It is important to note that you can always call for help regardless of your swimming ability if you need assistance in the water.
If you are caught in a rip current and need assistance, stay calm (as noted above) and get the attention of a lifeguard or beach patron on shore.
If you are on shore and notice a swimmer who needs assistance, you can always directly dial 911 for immediate assistance from Ocean Rescue.