Rip currents, or riptides, are narrow channels of water that move away from the beach as fast as 8 feet a second and can happen at any beach with breaking waves. They are hard to spot and can be very dangerous. Just the other day, four people in Biddeford were rescued from a rip current by lifeguards and transported to the hospital. They all lived, but that's not always the outcome. Last weekend, two people died and several others were rescued when they got caught in rip currents at Seabrook Beach in New Hampshire.

There are several measures you can take to avoid being caught in a rip current. The obvious ones are:

• Learn to swim

• Never swim alone at a beach without lifeguards

• Check tide conditions online before you go

• Pay attention to cautionary signs posted on the beach

Before you do find yourself in the middle of a rip current, watch this video on how to survive one. It advises above all to stay calm; the current will not pull you under, it will only sweep you away from the beach. Rather than panicking or trying to paddle against it, NOAA officials advise you to swim out of the current by going parallel to the beach and back toward shore at an angle.

Rip currents can be deadly but if you know how to escape if you do ever get caught in one, you will have a much better chance of surviving them. As always, be vigilant in your safety practices when swimming in the ocean and do your best to spread the information to others.