There have been several drownings in local lakes lately and all report that people fell in the water and never resurfaced. In once case a person fell off a platform into the water. In another, a person fell out of a boat and two others jumped in to save them.
How can it be that people don’t surface? Even if these people didn’t know how to swim I’d think they’d at least flounder on the surface before drawing.
Riptides/rip currents/under tow
How many of these people do come back up, they’re just miles away and never found?
Also, some people just don’t float well. I have several friends who, if they’re not actively trying to stay on the surface, tend to sink like rocks. For them, it might be: Fall in, hit your head, pass out underwater, and then you just stay there.
Humans don’t always float. It depends on how much muscle and fat you have, how much air is in your lungs, and what you’re wearing. Humans do usually flail about when drowning, but it’s easy to get disoriented underwater and flail downwards when you think you’re flailing upwards.
People have a bit of unexpected behavior when drowning. Rather than flail around, they sort of bob up and down doing a kind of vertical doggie paddle. People watching may not have any idea that the person is actually drowning. It has something to do with a reaction to getting water in the air pipe trigging a primitive part of the brain taking over control. Although not exactly the same, you can think about the uncontrollable reaction people have when being water boarded. There are certain situations which create panic in the brain and automatic behaviors take over. A person who falls in the water and breathes in a lot of water may enter this primitive drowning behavior and be unable to call for help or save themselves. This can even happen to experienced swimmers. Competitive triathletes who get an unexpected splash into their mouths when they are inhaling can drown because the brain switches to this panic mode and they are unable to save themselves.
Another aspect to this behavior is that the drowning person will desperately try to climb onto anything nearby, which may include rescuers. An untrained rescuer may be pushed underwater by the person and themselves start to drown. Rescuers should use some kind of flotation device that they can push to the drowning person so that they can stay a safe distance away.
If someone goes in feet first with shoes on and gets stuck in the mud on the bottom they might not come up until their ankles rot. I’ve swum in lakes and ponds with some very deep and sticky mud on the bottom and you learn right quick never to try to stand up in that muck. Be a nonswimmer going inadvertently into the drink and I’d say it would make perfect sense they don’t come up.
A child did that to me, but she heeded when I asked her to float and hold onto me while I dog paddled back to a dock.
I was in a survival swim course in the Navy and the instructor said everyone floats, but some just float deeper than others. He also demonstrated (and we copied) how tensing your muscles causes you to sink. Combine the two, and there ya go…
When we’ve snorkled, everyone is amazed by how my lovely wife sinks like a rock.
The person I know who fell in the water and didn’t resurface was intoxicated.
Either some undertow current, or they’re weighed down by something they’re carrying or wearing.
Cloth itself can be a tremendous drag. I’ve never heard of it actually happening but a bridal dress, for instance, could very easily drag a person totally underwater.
Somewhere, where I can’t find it, there’s video of Jeremy Wade showing how remarkably little weight is required to turn most humans from ‘bobbers’ into ‘sinkers’ in fresh water.
Every year on the first few hot days of summer we all wait for the first drownings in the rivers, usually at High Rocks in Gladstone. It might be a hunnert degress out but the water is more like barely melted snow and at High Rocks the idiots drink a few beers, get nice and overheated, then they leap off the high rocks (wonder where the place got its name lol) into the very deep, very frigid water. Funny thing, when you’re overheated and a bit inebriated and you hit deep water that cold with no easy way to get back out the chances are very good you are going to seize up, blow your breath out, sink like a rock and find out the hard way that humans are not capable of breathing water. Every. Fucking. Year. There are signs, there are warnings, there are lifeguards, the Clackamas Sheriff’s Department deploys a rescue boat out there when it’s likely to be crowded and yet every damned year at least one person drowns there. Multiply by all the other deep, cold rivers in Oregon and it adds up to quite a bit of watery carnage. If people would just wear a floaty they’d be okay but no, guess that’s too wimpy for the beer drinkers.
In my forties, I took basic swimming lessons with a small group of other adults. This was a very relaxed atmosphere with a no pressure, try-it-when-you’re-ready approach. There was a sort of jungle gym in the deep part of the pool so we could experiment with depth with relative safety.
And I quickly discovered that, if my lungs were empty, I sank and could walk for a few seconds at the bottom of the pool. If my lungs were empty but I made a conscious effort to keep my muscles relaxed, I sank more slowly. So floating passively on my back was mostly about controlling my breathing so that I had air for a large fraction of the time. Easier to do in the shallow end of the pool, for some reason. 
Falling off a ship, screaming while falling? Air knocked out of me by the shock? I may not be surfacing at all.
If I take a full lungful of air, and lay back at a ~45 degree angle with my head tilted back, I can just keep my nose above water. I start sinking as soon as I let out my breath even a bit. I can float efficiently for long periods by taking a quick 2-second breath every 20 seconds or so, but this is a pretty far cry from “some just float deeper than others”. If I wasn’t practiced with the trick and couldn’t swim, I’d probably just sink and die.
There’s a disturbing tendency for people who fall off Chicago’s Navy Pier to literally wash up on the beach in Gary, Indiana some months later. Apparently, there’s an underwater current between the two locations.
As just one example.
While I always floated easily–I had a lot of fat–I had a friend who not only didn’t float he couldn’t even tread water. I do believe everyone floats in salt water, but maybe not if they are fully clad with shoes. I once went into the dead sea and you don’t so much float as bob.
This is a crucially important thing to know, especially when watching a child or an adult non-swimmer in waters off a beach, or even in a swimming pool. Also true is the tendency of a drowning person to grab at a rescuer and potentially pull them down, too.
It’s also a myth that someone who is drowning waves his or her arms frantically. If you are drowning, your body is focused on helping you survive, so voluntary arm movements are difficult, if not impossible. In most cases, drowning people are vertical, not horizontal, and they try to use their arms to press on the water … in the vast majority of cases, people [who are drowning] are unusually quiet, often appearing to be relaxed, floating or treading water.
Speaking of those drowning signs…I was at the pool the other day and I saw this kid go off the diving board, and and as soon as he popped up the lifeguard jumped in after him. He was very confused, swimming just fine back over to the ladder… I had read these articles before when my son was little so I knew what it was. This particular kid came straight up from his dive and slapped down at the water with both hands. After the guard grabbed him the first time they talked about it for quite awhile, but it seemed to be a habit of his, and every single time he dive he’d bob up and slap the water like that; I could tell it made the guard twitchy every single time.
I was going to suggest intoxication, drug overdose, or medical emergency. The other thing that might happen in an accidental fall into water is a lung full of water. It could also trigger coughing underwater which is going to make it worse. Imagine someone falling over and yelling on the way in surprise and hitting the water with their mouth open.
I got stuck in a rip current as a teenager. A rip current is less powerful than a rip tide. I didn’t know what was going on but I was parallel to the surface facing up and I couldn’t break free. Panic ensued. I don’t know what made me think of it but I rotated so I was facing down and then reached for the bottom with my feet. I was able push off through it. luckily I was close enough to the bottom and it was only about 8-10 feet deep. I’m not sure if that started my claustrophobia or magnified it but it’s not something I want to repeat.
“Undertow” is a misused term, often wrongly applied to rip currents. In both cases, a current pulls swimmers away from shore, but it doesn’t drag them down.