Summer is the perfect time for swimmers to leave the pool and head to the ocean to swim some laps with their Underwater Audio Waterproof iPod. The water is finally warm enough to swim in, and is very refreshing on a hot day. A pool is a controlled environment, but the ocean is not.
Make sure you have mastered pool swimming before heading to the beach for your swim workout.
One of the biggest differences between swimming in a pool and swimming in the ocean is waves and unpredictability. Ocean waves are amazing and beautiful, but also dangerous. Here we take a look at what causes ocean waves.
Wind speed and duration help in determining the size and frequency of ocean waves.
Basically the more windy it is, the bigger and more frequent the waves will be. Another factor is a term known as “fetch,” which refers to the span of water over which a breeze blows.
The longer the fetch, the more energy a wave can have.
Waves come ashore as a result of the shape of the ocean basins. Water is pushed towards the shore as the basin becomes more shallow.
A good example of this is sloshing water in a bathtub. When some force is added to the water, the sloshing heads toward the edge of the tub and then goes into a back-and-forth motion.
Visible waves are only part of the wave. The wave actually extends down through the water all the way to the ocean floor. Waves start out in the deep ocean and are relatively vertical in shape.
As a wave travels to the shore, the bottom part of the wave drags along the ocean floor, causing the upper part of the wave to move faster than the rest of the wave. As the ocean becomes more shallow, the drag on the bottom becomes more powerful and the upper part of the wave begins to tilt forward.
Eventually is curls over, which is known as a breaker. What we see is the rolling shape of a crashing wave.
The water that’s tossed up on the beach by waves has to go back to the ocean.
It’s not a uniform process because water returns to the ocean where it’s easiest to do so, such as through a break in the sand, or near a pier or jetty.
In other words, water that hits the shore loses momentum and has to go back towards the ocean. A rip current is caused when the ocean floor funnels the water into a narrow stream, creating a dangerous situation for even the best swimmers.
To spot a rip current, look for water that’s frothier or darker than surrounding water and avoid the area.
If you’re ever caught in a rip current, DON’T fight the current by trying to swim straight back to shore. You’ll be fighting the current and exhaust yourself.
Instead, swimmers should try to leave the rip current by swimming parallel to the shore until you no longer feel the resistance. If lifeguards are available, wave for help. It’s better to be safe than sorry, no matter how good a swimmer you are.