Maybe this is where part of the problem lies. This is normal. I float very well, and have almost no body fat (and had even less in high school when I swam and floated even better.) When you lie back, your legs will start to sink. The key is to let them and not try to fight it. Keep a lungful of air, and your chest and head will stay afloat. Your posture when floating is essential.
I also see everyone mentioning floating on their back. Crazy as it sounds, have you tried floating on your stomach? You float better face-down. I remember my swim instructors in elementary and high school telling us that if the water was calm, and we thought it might be a long while before we get help, that face down will save more energy while floating. You obviously have to lift your head up every so often to breath, and if you don’t have a good lung capacity it might not be good, but I find it relaxing and easier than floating on my back.
And I’m fully capable of sitting on the bottom of the pool as well. A full set of lungs or an empty set of lungs works wonders for buoyancy.
A friend who taught very good swimming courses (for kids and adults) had a test he did with the adults* early on (after getting them used to water-in-the-face, one of the earliest lessons). He took them into the corner of the deep pool, where the bottom was over 3.50 meters down (ca. 3.5 yards), and each person went slowly into the water, holding onto the edges, then took a deep breath and pushed downwards, until the head was under water, and the air in their lungs + the fat buoyed them up again. It was quite impressive to see the relief as they realized they would pop back up like a cork.
Important notice: the position of your arms - to the side or over your head - plays an important part in this.
Although I can swim well, I, too, was surprised by this, because I’d only ever tried vertical (Dead man’s float), where you have stay rigid, otherwise skinny legs will sink.
He said that the body-fat rate for children is not good enough for this test.
Generally, I think that people who act all phobic about not being able to swim, or being able to learn, should get a grip and a good, sensitive teacher with a well-developed training plan. (No, my friend doesn’t want to do it anymore, he’s fed up. And he’s in Munich.)
I posted my OP a wee bit late, as I was doing a lot of thinking about this last summer. I tried a neat little experiment, and I’d encourage chronic sinkers to try it too. I’d be interested in the results.
Go to the deep end, or at least to where you can barely touch bottom. Hold on to the side of the pool loosely. Relax your body and let it do what it wants. When it has settled to wherever it wants to be, take a breath and stick your face in the water. Again, let your body do what it wants. Don’t force anything. After a minute, take your face out of the water. Then back in.
Former lifeguard and swim team member - I sink like a rock if I try to float motionless on my back. Everyone, however, will float near the surface if you hold your breath and lean forward. I don’t know if they still teach this, but, the sinky-floaty routine is the best way to not drown and conserve energy if you are going to be stuck in the water for a long time. It takes a lot of energy to keep your head out of the water full time. If, instead, you put your face in the water, let your arms float next to your head, and, as much as is possible, try to “lean forward” so you don’t go completely vertical, you will, depending on your body fat, either float on the surface, or float very close to the surface. When you need to breathe, exhale, then simultaneously lift yourhead, push down gently with your arms, and give one gentle scissors kick. This will raise your head out of the water. Take a breath and lower your face back into the water. Repeat as often as necessary. The key is to not kick and push so hard that you raise your head too far out of the water or else you will start to sink as you come back down. If you do start to sink, don’t panic. You will slowly rise back up to the surface, or near the surface depending if you are a natural floater or not.
Even for a bunch of experienced swimmers, this took a little practice. The key is to minimize the upward movement to get your breath. The higher you raise your head, the further you sink afterward. Slow, gentle movements and you can sustain this for hours and hours. You can’t tread water and keep your head out of the water for that long.
Body fat does play a significant role in buoyancy. When I was doing DM certification, one of the exercises was to tread water for 15 minutes, and you got the highest mark for doing the last 3 minutes with hands out of the water. I could do this easily with just a light kicking motion and a moderate bit of bobbing; the slender Asian girl who was in the cert with me could barely tread water even using her hands. Technique (as described by oboelady) and comfort in the water also play a role, but some people simply don’t float head up while others float naturally.
I don’t know if this is true, and I can’t remember where I read it (Fouts, I think), but supposedly the reason that chimpanzees can’t swim is that they have no body fat. Apparently, they literally do ‘sink like a rock.’
Family legend has it that I have an ancestor who was so obese that he could float on his back in the Caspian Sea and actually catnap while doing so. :dubious:
Human buoyancy is going to be a function of both body fat and body muscle.
Body fat density is ~ 0.9 g/cm-3 which is just slightly less dense than water (which is exactly 1 g/cm-3). Thus, if one were to put a chunk of fat (let’s use steak fat) in water, the chunk would float.
Body muscle density, on the other hand, is slightly more dense than water at ~1.06 g/cm-3. A piece of lean meat from the same steer would therefore sink in the water.
The other types of tissue play into this as well, but it seems to me (haven’t studied it) that these would not vary quite so much from person to person as muscle and body fat do. (Blood looks to be slightly more dense than water)
Since one’s ability to float in water is a function of total density, then buoyancy becomes a function of what percentage of the body mass is muscle and what percentage is fat. If there is a great deal of muscle and little fat, the scales (so to speak) are going to tip over to the more dense than water side, and the person will sink. If the percentage of fat is higher, at some point the density will become less than water and the person will float. This also means that some people are close enough to a density of one that the a deep breath in can be the difference between sinking or floating.
Speaking of witchcraft… Healthy women in general have more body fat than healthy men with comparable body profiles. I believe that in general, healthy men are likely to sink, whereas healthy women are almost guaranteed to float. This means that the old test of throwing a tied up witch into the water would be less likely to show one of the menfolk as a witch
When I was taught swimming as a kid, our coach made us take a deep breath and then grab our knees in a sort of foetal position. All of us were bobbing up and down like mushrooms with our backs above water. It was a great confidence-building measure and let us know that it needed no effort to float. We were pretty average physically, and age was about eght years. I don’t know what sort of difference this might make.
I just talked again to my friend, and he confirmed: no human, no matter what the fat-muscle-bones to total body weight ratio is, will sink as long as air is in the lungs. Non-swimmers who do sink are probably so tense that they exhale. And if you are tense, it will feel more difficult to stay above water.
Technically, children before puberty (plus marathon runners, rock climbers and similar adult sportspeople with lots of muscle, low total weight, little fat) have the worst possible ratio of fat to total body weight, yet my friend has taught hundreds of the little buggers to float and swim. So yes, if 8-year old kids can float, any normal adult with air in his lungs can float.
And learning to swim is not directly related to floating anyway - an obese blob of 250 kg will float comfortably, but too limited in his motion range to swim effectivly.
The tenseness and lack of coordination for the new set of movements is what makes swimming difficult for beginners. Practice helps, not fat. And a good teacher who does confidence-building exercises like the one above.
I’m one of the sinkers. I also happen to love the water and love swimming. When I “relax and let my body do what it wants” it doesn’t end up floating.
Luckily, I find this position comfortable and peaceful…meditative (like I said, I love the water). But it isn’t floating the way I’ve seen other people float, or experienced it in a wetsuit. (The first time I wore a wetsuit, I was supposed to be practicing swimming in one. I didn’t because the sensation of floating was so novel, I just played around with not sinking.) And if I were a more panicky type of person, less confident of my ability to swim, or didn’t really like the feeling of being surrounded by water, I would be freaked out by other people’s claims about what my body should do in the water when it obviously wasn’t doing that. I’d say that such advise is incredibly unhelpful.
When I was at Air Force Field Training (“officer basic”) in Texas, we spent most of July marching around, eating very small meals, doing extensive PT, and generally sweatin’ to the oldies. Going into camp I had been a skinny mumblethumper, but by Training Day 20, when we got into Water Survival, I was probably down to 160 pounds with maybe 2 pounds of fat if I’d had bacon for breakfast.
We got into the pool and the Lieutenant showed me the dead man’s float, which I had been doing in the Atlantic since I was four or five years old. I said “Yes sir, I know how it’s done, but it’s not working.” The LT came over to give me some motivation and yelling, and finally asked to see what I was doing wrong. I splayed out and sunk right to the bottom of the pool. The LT laughed, asked to see it once more, and then said “You’ve got great form, but if your plane goes down over water you’re a dead man. You get a pass. Now help your flight-mates with their form.”
In retrospect, I was probably not filling my lungs very full of air; I was a long-distance runner and in the water I felt more comfortable with a half breath than a full chest-bursting inhalation.
I’m so floaty I have trouble duck diving. I can do a pin drop and end up with my head bobbing above the water. I suppose that if I were ever lost at sea there would be an advantage in not having to tread water.
I think that this is far more important than the increased muscle mass, unless you had been used to pool swimming before this test. In salt water like the Atlantic, because of the increased buoyancy, you move slower than in sweet water like a pool.
My friend said how when he spent several weeks in summer in Yugoslavia swimming in the Med., and then returned to Munich’s sweet water pools, he felt as if the water had “holes” through which he kept sinking, until he had gotten used again to sweet water.
That’s because it’s difficult to give advise over the internet, instead of watching directly what you’re doing. From the other description above, I suspect many people who are tense simply don’t beath in well enough to fulfil the physics. Also, if you’re tense and unsure, it’s difficult to stretch out, which helps floating.
Or, you’re a medical/physical oddity to every textbook. (Posting a video to youtube of how you’re sinking won’t help me, because I can’t watch youtube on my system and with my connection.)
Hey, Just thought i should chip in.
As a child i remember doing the exact same thing. and i remember floating.
Now i sink like a stone, big breath or none. if i take a lung-burstingly big breath in fresh water i still sink.
On the plus side, us sinkers can work on blowing bubble rings from the bottom of the pool with a our lungs full. floaters need to waste air to sink and so have less to blow rings with!!!
obviously I’m doomed if i pass out at sea.
I’ve been reading about free-diving, and I’m thinking that a sinker can’t free-dive without armbands or a wetsuit
I’m another that sinks like a rock - I sink a bit slower than when I was twenty or so, as I’m not quite as lean as I was then.
It takes continual effort to stay afloat. I hear of people floating and treading water for hours on end, and it is simply incomprehensible to me, as I would be totally exhausted, to the point of drowning, in a relatively short time - not sure just how long, as i have never tried it…
42, 195#, 5’5" stocky build. Charts say I’m 40-50 pounds overweight but I was Army fit back at 170#.
If I lay back straight, head and chest tipped back, full breath of air, My legs sink quickly and only my face from the ears forward is above the surface. I exhale, I sink like a rock.
Hairy beer gut notwithstanding, I can swim like a fish. Well, maybe a walrus.
I’ve been swimming comfortably since I was 5 (and boy, are my arms tired!). I’m not afraid of the water, I don’t tense up, I have plenty of lung capacity (I’m a runner), and as far as I know, I’m human. But I can’t float without at least some effort at treading water.
If I assume the spread-eagle positon, face up, my midsection/butt will sink first and pull the rest of me down after it, even while holding a deep breath. I won’t go to the bottom, but will hang out subsurface. If I try to sort of ‘pelvic thrust’ my midsection up higher, my head and legs will cantilever down under the water.
For a long time I thought “floating” always involved at least some minimal water-treading efforts, until some friends and I got into the conversation while in the pool. I witnessed them actually floating on the water, while making no effort to stay like that. Try as I might, I just couldn’t do it.
Your friend’s expertise notwithstanding, I just don’t think his comment applies to everyone.