Following a recent painful experience while traversing the air-water interface at speed (it still stings…), my feeble mind set off along a morbid line of thinking. Stay with me here.
We’re talking human body hitting the water surface at speed here. Falling from below a certain height, I figure that the chances of survival are good. OK - it might hurt, or even cause minor injury like dislocated fingers, but would be unlikely to kill you. Now…following the same reasoning, there must also be a height above which no amount of fancy diving technique is going to save you - you’re a goner. So far, so hoopy.
This leaves a (possibly) quite considerable range of heights between these two limits, for which the attitude/method of water entry might make a difference between survival and ‘failed to resurface’, so to speak.
This might be one for someone with a military background - I’m sure they’ve thought about this. What is the best possible attitude or position for the Mark I Human Body to enter the water at high speed? Head/hands first? Feet first? Possibly even Foetus Firstus? Does anyone know what kind of fall into (deep) water could be survived using the appropriate technique?
In the meantime, I’ll just stay off the Harbour Bridge…just in case.
Hands first. Keep your body straight. Outstretch your arms in front of you, and clasp your hands together, eyes closed on impact. This should provide minimum resistance to the water at the surface.
I could see problems with keeping either arms together or feet together when entering water at speed. Having your arms/legs set off in different directions as you enter the water could lead to “severe structural damage” at the kind of speeds I’m thinking about here. Another problem with feet first+pointy toes+hands held along sides would be that the first point of resistance would be your chin, leading to head snapping back and broken neck.
Morbid…but might come in useful one day. I wonder what kind of height all this comes into play? Jumping off a large ship into water? An oil rig? hmmmm
Just brought to mind a ‘Far Side’ cartoon…a cat falling through the air, feet firmly aimed down, fur streaming up, a surprised look on its face, with a airplane just visible in one top corner of the frame. The caption? “Fluffy suddenly realised that it wasn’t going to matter if he could land on his feet from 10,000’ up”
Seems to me head first with arms outstretched above the head would be best. This would give you a sort of arrow shape and keep water resistance minimized.
Recruits at Parris Island doing water survival training go in the pool from a reasonable height feet first, one hand covering mouth/nose, and the other arm wrapped in front of the elbow, grasping the upper arm. I’ll pause now while you all assume that position.
OK, I THINK they cross their feet, also. I think this position keeps your head from filling with water. I would try to end up in this position if I had time to think about it and get there.
Ummm, that of course assumes you are falling from far enough up that drag would come into play and you’d have time to assume a number of positions as the situation warranted. I believe that was implied in the OP.
Judging from my experiences at hang-gliding involving many ‘unexpected groundal encounters’ (aaargh - I’m starting to sound more like gee doublya every day…), I’d say my depth perception isn’t good enough to go through all the different positions on the way down !!
Leaving that final transition from ‘drag-maximization’ into ‘super-streamlined’ just a moment too late could be…er…messy.
I haven’t heard anything convincing so far about best position to increase chances of survival into water from great heights. That doesn’t mean I’m volunteering to do extensive first-hand research on the matter, however…
As I said in my original post, there must be a range of heights for which this makes the difference between surviving or not.
I was not in the navy, but a guy who was told me the “abandon ship” posture was feet first, one hand covering the testicles, the other arm over the face. The assumption is debris and other people in the water, and you might collide with them. No points for style, but lack of injuries count for a lot. If some part of you has to get crunched, legs are better than heads.
In the novel Rendezvous with Rama Arthur C. Clark descrives comething along the lines of the OP; the solution was that the bloke jumped off the cliff holding his unzipped jacket outstretched with his arms; like a mini-paracute; at last second he let go the jacket and splashed feet first.
Of course the gravitiy in Rama was lower than Earths.
If you interested in this kind of stuff, see if you can snag a copy of “The best case survival handbook”. Its wirtten by an ex-navy seal telling you about what you should do in situations like this.
IIRC, he advised that you should go in feet first with one hand holding the nose
Thanks pokey - THAT is what I was looking for. I was sure that someone, somewhere, must have done some work on this.
Feet first sounds more plausible to me, and I should be able to do a back of the envelope calculation to work out the approximate height required to reach a velocity of 70mph. If it takes 500 feet to reach a terminal velocity of ~120mph, that suggests that many falls from bridges, etc., into water could be survivable provided you hit feet first.
For example, the fall from pedestrian walkway height to the water off Sydney Harbour Bridge is about 160 feet (had to convert to imperial for our US correspondents - reference another thread on here…lol), which sounds survivable.
Something to think about as you are hurtling down, anyway…
I just realised that the terminal velocity of 120mph is for the spread-eagle skydiving position, but could be as high as 180mph for a streamlined head first power dive.
So, adopt the skydiving position on the way down to maximise drag, then bring arms around in front of you on nearing the water to rotate the body into a feet first attitude for best chances of survival…simple !!
Not to complicate things, OK to complicate things, but not only do you have to survive the impact, you have to succesfully surface. These subjective variants (given lung capacity, shock reaction) alone, merit your question as being one only proven by repeated scientific experiment. One’s capacity for surviving a fall from ‘x’ feet, cannot be known without knowledge of said persons physiology. Granted, this may be nit-picking, but it seems to me that a knowledge of how to enter water at great heights would be almost useless without training on how to survive the re-surfacing.
It’s not the fall that kills you, it’s the landing.
P.S. A pilot friend of mine told me that it’s better to land in dirt than water, being that water is incompressable. Sounds reasonable, don’t mean to hijack.
Saw a Discovery Health Channel show about “Near-Fatal Mishaps” or whatever they called it – one guy was BASE jumping from a 200-ft. bridge and was so busy watching his friend who jumped with him, that he, umm, forgot to pull his own ripcord. SPLAAAASH!!!
In addition to numerous broken bones, his most significant injury was a giant HOLE IN HIS RECTUM torn open by water shooting up his anus. The show went into loving detail describing that injury and how they fixed it.
I need to stop watching the Discovery Health Channel. :smack:
