Rip current?


What the heck is a rip current/riptide and why are they so deadly? I just googled it and I’m still confused.

In: Physics

Sometimes, a current forms on and near the surface of an ocean that pulls the water and anything in it rapidly away from the coast. This current can be caused by a lot of factors.

Anyone caught in the current is in a dangerous situation, because they can quickly be pulled too far from the shore to swim back before exhausting them self and drowning; especially if they try to fight the current by swimming directly against it.

Anyone caught in such a situation should instead try to swim at a 90 degree angle of the current (parallel to the shore). This gives them the best chance of getting out of the area of the current. Once they are no longer being sucked out to sea, they have a higher chance to make it back to shore safely.

The water from the wave has to go somewhere after it hits the beach, it washes back out underwater causing the water to pull you away from shore. They are deadly because they can pull you out to deep water or pull you underwater.

A beach often has underwater sandbars running parallel to the shore. These sandbars are long and skinny and separated by gaps. When the waves come in, they lift water up and over the sandbars toward shore. The waves start to ‘break’ as they pass over these sandbars and collapse into foam and surf running up onto the beach. The water in the wave has to go somewhere but it is trapped between the shore and the sandbar. It runs sideways until it finds the gap between sandbars. At the gap, it runs under the waves and out to sea. The gap may look like calm water because it is deep and no sandbar breaks the waves but it is very dangerous.

Because the gap is narrower than the long skinny sandbar, there is more water going out at the gap than is coming in over any particular point of the sandbar. As a result, the water current pulling you sideways into the gap and then out to sea through the gap is very strong. This current is called a riptide.

The riptide is deadly because while you are swimming it pulls you sideways into the gap and as you get nearer the gap the current gets stronger and the water gets deeper. Unsuspecting people may find themselves knocked over, pulled under as the current passes under the waves, and then swimming out of their depth and swept out to sea. This causes panic and drownings.

When pulled out to sea by a riptide, even strong swimmers may become exhausted and drown because they try to swim directly back to shore. This happens because they remain in the rip current which keeps pushing them out to sea. The solution is to swim parallel to shore to exit the riptide, then back into shore over the sandbar.