It's a really strong current that usually comes as the result of a hurricane. It's very hard to get out out once you're in one because it takes all of your strength to swim against it. This one was weird because it didn't go in a straight line towards the shore but more north to south along the shore and maybe a 1/4 mile in length. So the lifeguards were making everybody was swimming and boogie boarding move down the beach so as not to get caught in it.
......and that is my scientific explanation! HAHAHA
Did you get up and dance when you heard The Love Shack come on?