I can attest to this method. Similarly to the GP, at some point in my early teens while swimming at a small lake, I decided to try swimming across the lake (more of a cove) and back. I was never a great swimmer but I was confident I could make it because I knew I could just flip over and leisurely kick if I got tired. Sure enough, my arms started to burn about halfway across, so I just flipped over and eased the rest of the way.

It's not nearly as fast as "proper" swimming but I'm sure I could keep it up approximately as long as I could walk. Maybe even longer. It makes for a great option in dangerous situations, and is likely a good fundamental technique to teach anyone just learning.

Everyone should be taught this technique.

Nethertheless: I did this in the ocean once about 200m off the shore (at that point I wasn’t really in trouble and just wanted a rest) and the waves were too high and I ended up eating a lot of salt water and nearly choking and sinking. It put me in a far worse situation than had I stayed off my back.

The lay on your back technique works for those who it works for, and it should absolutely be taught to everyone just so that whoever it works for knows about it and uses it when they find themselves in a situation when it could save their life. Less drowning in calm waters is a net positive. But there is a percentage of the population who can’t simply float.

Some of us literally sink if we don’t swim.

One time my friend looked at me in awe as I laid on my back, relaxed, and sunk. We tried it over and over again. I was as curious as she was. She had to put her hands under my body to keep my body above water. When she removed her hands I’d begin to submerge, just laying on my back, arms stretched out, until I was fully underwater. But she did the same and she would float.

I wasn’t tense, but rather relaxed and not panicking, since I could swim (the only way I know to stay afloat) and knew she was right there. And I mean, not that hard to just lie there calm and relaxed. I have to actively swim in order to stay afloat. And I’m not the only one..

Although strangely enough dead bodies float so what’s up with that?

Fat and air float. Muscle and bone sink. Your overall buoyancy depends on your particular combination of lung capacity, fat, muscle, and bone. Also, fresh water is not as dense as salt water, so it is more difficult to float in.

Decomposition produces a variety of gases that increase buoyancy.

It’s not just bones and muscle. Fat has different densities, too.

I have very high density fat. Although I’m more than 100 pounds overweight, I still sink like a rock when I get into the pool and exhale. If I inhale a lot of air into my lungs, I can usually keep my nose and mouth barely above water, but not much more.

In contrast, my wife is also overweight, but her fat is low density. There is nothing I have found that is capable of making her sink.

The times we have gone snorkeling, I have no problems diving and I have to work to surface. But she can’t dive for love or money, although she can get her face fully under water.

My feet sink if I try to float on my back w/o swimming. But there's another float called the dead man's float that works fine for me. It also works well in rough water:

https://www.sportsrec.com/survival-float-6582.html

Thank you for this. I don’t think we tried this technique — but yes my legs are usually the first thing to go down, pretty much instantly. And I have a shorter torso, longer legs (when I sit down with someone several inches shorter than me, we are at the same eye level)

A bit of air in your lungs will make you more buoyant.

True, but it doesn't help staying afloat. If I lay on my back, my feet and legs will sink first.

Have you ever tried tilting your head back farther into the water & swimming with your feet slightly?

These 2 things are the difference for me between sinking & floating. Mostly tilting my head further back though.

Of course this fails miserably with even the smallest waves.

That’s one of the things we tried. My head was tilted so far back at one point that water started running up my nose.

I'm a tall, lanky guy and I can't float at all. Well I do float, but my point of neutral buoyancy is with my head a few inches below the surface.

That said I learned to properly tread water while getting my open water SCUBA cert and turns it it's really easy. Last time I tried, from completely fresh, I was able to tread water for 40 minutes before I got bored and quit. I probably could have done it for another 40 minutes, at least. This was in a pool though so I was relaxed and the water was calm.

This technique got me through Jr. Lifeguards. I would pretty much immediately get hypothermic in the ocean, turn blue and feel as if I couldn't breathe. I would float on my back and "jellyfish" - essentially flapping your arms in sync, sometimes doing a breast-stroke kick with the legs.

If the ocean isn't too rough, and you conserve your energy for dealing with waves, this works pretty well.

I think the skill of being able to flip onto your back and scuttle to wherever you need to go is more important than knowing how to swim (and I love to swim - I swam 2 kilometers just this morning). Unless you are in super cold or choppy water you should be just fine.

I have some very young nephews. As well as teaching them how to swim, we're teaching them how to flip over and float, just for this reason. If they can do that, and recognise when they're in trouble, then it might just save their lives one day.

Don't forget teaching them how to swim on their backs.

You can also swim on your back and it tends to be much less tiring than swimming normally.

Once I learned the "elementary back stroke" I felt that I could safely swim in water again.

Something I learned as part of the swimming merit badge :)

This doesn't work for me. I was put on Concerta for 8 years, which essentially eliminated my appetite, so my bodyfat% is low enough that I sink in water unless I take very shallow breaths while keeping my lungs very full (90-100%). Otherwise, my head floats low enough that my mouth is underwater, or I downright sink to the bottom of a pool.