When I was at the beach in North Carolina over the summer, for a couple of days there was a sign outside the lifeguard stand that said WARNING: RIP CURRENT. Now at the time I wasn’t exactly sure what a rip current was, all I knew was that it was obviously dangerous and it pulls you out into the ocean. So, I still went in the water because everyone else didn’t seem too worried about it. While I didn’t get pulled out into the ocean by the rip current, I did get a bad sting on my leg from a jellyfish (and it hurt!).
Well, rip currents involve radiation stress, which is the force exerted on the water by the wave. Rip currents are powerful currents of water that narrowly run from the beach out into the ocean. They occur when there are variations in the patterns of the waves breaking, and large waves break closer to the shore. All of the water from the crashing wave wants to find the path of least resistance back to the ocean, causing the rip current. The force of the rip current depends on the height of the wave; the larger the wave, the greater the force of the wave, and the greater the force of the rip current. If you ever find yourself stuck in a rip current, don’t panic or swim straight back toward the beach like you would think. The force of you swimming in the opposite direction of the current is not large enough to get you to shore, the rip current has a much greater force. Instead, swim parallel to the shore until you get out of the current, or float out with it, and then once the current stops, swim diagonally back to the beach.