Скачать или смотреть Water Safety — How to Escape Dangerous Currents (July 2024)

More on this Great Lakes-focused series via the NYSG news item, "On YouTube: Beach and Water Safety — Know Before You Go", https://seagrant.sunysb.edu/articles/....

Transcript:

Lake Michigan is freshwater. This is so different from an ocean. We don't have the salt, so we're lacking that buoyancy already, so if waves get super high and rip currents start to form and that water gets volatile, if you start struggling when you're swimming, it's going to be so much harder to get out of that situation.

In the ocean, you could have 15 seconds between the crest of a wave and the crest of the next wave, but on the Great Lakes you might have a swell period of 3 seconds to the crest of one wave, 3 seconds to the crest of the next wave, and 3 seconds to the crest of the next wave.

We call this a high frequency wave. So in the ocean, 15 seconds you get hit with two waves, but in the Great Lakes you could get hit with five waves in the same time period.

The higher frequency can be very traumatic and it can cause very strong dangerous currents.

The current and wave combination on the Great Lakes can be deadly, but there are some tips that you can follow to keep yourself safe from dangerous currents when you're swimming in the Great Lakes. The first thing is to stay dry when waves are high as dangerous currents are more likely once waves get to around 3 feet. This may not seem very big, but it's often the time most people get into trouble because the currents can become active and it doesn't look like the waves are that big, and so it doesn't look very threatening, but actually about 80% of our incidents happen when those conditions are present.

It really can be difficult when you're out there trying to swim against the strong powerful water energy of Lake Michigan.

There are several different types of currents that can cause a swimmer trouble on the Great Lakes. Rip currents are responsible for around 40% of the drownings on the Great Lakes. A rip current can be tricky to identify even for the experts. Oftentimes, it looks like a calm spot in between breaking waves, and people put their kids right into the current or walk right into it because they think it's safer than swimming in the waves.

If you get caught in a rip current — flip, float, and follow. You're going to want to flip on your back, let that water take you back, float backwards, and then follow, which means you're going to want to swim parallel to the shore out of that current, and then you can easily swim back to the shore and save some of your energy that way because you weren't fighting that strong current.

Longshore currents are currents that flow parallel to the shore. If you're caught in a longshore current, you'll notice that you're floating along the beach. Swim back to the beach to get out of the current, but make sure it doesn't carry you down the beach too far.

One good tip is to keep an eye on your belongings, this will help to know if you're drifting towards a pier or break wall where the longshore current can sometimes take you.

A structural current is a current that forms right next to a pier or break wall, and this happens when the longshore current which flows parallel to the beach intersects that pier or structure and goes out into the lake. The water has nowhere to go, so if you're jumping off the pier you could be jumping right into one of those currents.

Outlet currents form near river mouths or stream outlets, and it can be enhanced just like a rip current channel can when there are larger waves coming in at a direct angle, so we recommend that you don't swim near river outlets because the water can pull you out just like you're in a rip current.

Channel currents form in areas that are connected by a sandbar, so the shore will have a sandbar going out to maybe a set of rocks or an island. Oftentimes, people are walking out on a sandbar and get caught and pushed off the sandbar from that current, which is moving parallel to the beach. If you get pushed off a sandbar, don't panic — flip on your back, float, and follow the current until it's safe to get out of the water. To avoid getting caught in a dangerous current we should avoid swimming in places that they commonly form.