5 ms·

What happens if you are over water? Can you get some horizontal speed and try to skip across the water?

by sunnyP 7y ago

NateEag 7y ago
You hit the water at terminal velocity. Since water is effectively uncompressible, this is much like hitting concrete, I've read. You are either instantly killed or knocked out, in which case you slip underwater and drown. I suppose hypothetically your best bet over water would be vertical entry, as opposed to the spread-eagle recommended for a land impact, but at the speeds you'll be going I imagine you're pretty much doomed regardless - even if the impact doesn't shatter you, I believe water rushes into your internal organs through your anus and causes massive damage. I've seen that referenced as a risk for bridge jumps and this is, obviously, as bad a water jump as you can make. I also imagine you'd go deep enough that you couldn't possibly float back up to the surface before drowning, and I imagine the impact and pressure of increasing depth would force all the air from your lungs anyway. Disclaimer: I am not an expert in any relevant field. I may well have some facts wrong. Just speculating based on what little I know.
- delinka 7y ago
  I think you completely missed the horizontal part of the question.
  - NateEag 7y ago
    I thought I had addressed it, but I guess I wasn't clear enough. Whether you can skip or not, the impact will almost certainly kill you. The only question is whether your corpse will bounce and if so, whether it will do so horizontally. The article itself talks about horizontal traversal and saris you could make as much as two-thirds of your vertical traverse horizontally. If true, that means you can't even reach a forty-five degree descent, which I'm pretty positive would mean no skipping.
- spqr0a1 7y ago
  By conservation of momentum you won't go much deeper than diving from tamer heights. Still plenty of other trouble to deal with. https://en.wikipedia.org/wiki/Impact_depth https://en.wikipedia.org/wiki/Impact_depth
  - NateEag 7y ago
    Ah, makes sense. Thanks for the info!
- Mediterraneo10 7y ago
  Some two decades ago, I remember seeing a news report about a weird tight-knit community of BASE jumpers in the USA who liked jumping from high bridges without parachutes. (The reportage was mainly about how they were addicted to this activity like to a drug, and wouldn’t stop even though several members had died.) In order to make the surface of the water safer to land in, they dropped a heavy object a split second before they themselves jumped, as supposedly once the surface had been broken by the splash of the initial object it was momentarily not concrete-like hard. Anyone else remember who this group was and has some information about them?
- debatem1 7y ago
  Falling from an airplane is basically the same as falling from 1500 feet in terms of velocity. The highest dive ever is approximately 200 feet, and the list of injuries others have taken trying to match that figure is quite impressive. That suggests to me that the odds of surviving, no matter how practiced or proficient you are, would be very low over water. Of course, there are things you could do to improve your odds. Placing yourself near other people who might assist you would be a big one. If you could somehow make yourself float face up once unconscious that might help as well, although I struggle to see how you would do that given the colossal forces involved. Any kind of crush core would be a huge help. The horizontal component seems like a red herring when it comes to water. Any advantage you might get from the smaller vertical component would be totally overridden by the horrible death you would suffer due to damage to your internal organs.
zubspace 7y ago
Your best bet would be to hit the water like a needle because you can't reduce the vertical velocity in any meaningful way without a wingsuit. The chance is high that you'll break an arm or leg and lose orientation underwater, so be prepared. Maybe its better to keep your arms straight up but thats just a guess because I never tried. You will probably also need to stick around for a long time until help appears. Good luck! There's a fascinating story about a fighter pilot named Judkins [1] who survied a free fall above the ocean. There are other similar stories [2]. A lot of luck involved each time. [1] https://news.ycombinator.com/item?id=15480334 https://news.ycombinator.com/item?id=15480334 [2] http://www.greenharbor.com/fffolder/amazing.html http://www.greenharbor.com/fffolder/amazing.html
achikin 7y ago
There was such a case in Russia several years ago. An experienced skydiver was filming his friends and fell out of a helicopter without a parachute. He has landed in a pond and died immediately. It was said that the impact was so hard that it has torn off his jumping suit.

What happens if you are over water? Can you get some horizontal speed and try to skip across the water?

by sunnyP 7y ago

What happens if you are over water? Can you get some horizontal speed and try to skip across the water?

You hit the water at terminal velocity. Since water is effectively uncompressible, this is much like hitting concrete, I've read. You are either instantly killed or knocked out, in which case you slip underwater and drown. I suppose hypothetically your best bet over water would be vertical entry, as opposed to the spread-eagle recommended for a land impact, but at the speeds you'll be going I imagine you're pretty much doomed regardless - even if the impact doesn't shatter you, I believe water rushes into your internal organs through your anus and causes massive damage. I've seen that referenced as a risk for bridge jumps and this is, obviously, as bad a water jump as you can make. I also imagine you'd go deep enough that you couldn't possibly float back up to the surface before drowning, and I imagine the impact and pressure of increasing depth would force all the air from your lungs anyway. Disclaimer: I am not an expert in any relevant field. I may well have some facts wrong. Just speculating based on what little I know.

delinka 7y ago
I think you completely missed the horizontal part of the question.
- NateEag 7y ago
  I thought I had addressed it, but I guess I wasn't clear enough. Whether you can skip or not, the impact will almost certainly kill you. The only question is whether your corpse will bounce and if so, whether it will do so horizontally. The article itself talks about horizontal traversal and saris you could make as much as two-thirds of your vertical traverse horizontally. If true, that means you can't even reach a forty-five degree descent, which I'm pretty positive would mean no skipping.
spqr0a1 7y ago
By conservation of momentum you won't go much deeper than diving from tamer heights. Still plenty of other trouble to deal with. https://en.wikipedia.org/wiki/Impact_depth https://en.wikipedia.org/wiki/Impact_depth
- NateEag 7y ago
  Ah, makes sense. Thanks for the info!
Mediterraneo10 7y ago
Some two decades ago, I remember seeing a news report about a weird tight-knit community of BASE jumpers in the USA who liked jumping from high bridges without parachutes. (The reportage was mainly about how they were addicted to this activity like to a drug, and wouldn’t stop even though several members had died.) In order to make the surface of the water safer to land in, they dropped a heavy object a split second before they themselves jumped, as supposedly once the surface had been broken by the splash of the initial object it was momentarily not concrete-like hard. Anyone else remember who this group was and has some information about them?
debatem1 7y ago
Falling from an airplane is basically the same as falling from 1500 feet in terms of velocity. The highest dive ever is approximately 200 feet, and the list of injuries others have taken trying to match that figure is quite impressive. That suggests to me that the odds of surviving, no matter how practiced or proficient you are, would be very low over water. Of course, there are things you could do to improve your odds. Placing yourself near other people who might assist you would be a big one. If you could somehow make yourself float face up once unconscious that might help as well, although I struggle to see how you would do that given the colossal forces involved. Any kind of crush core would be a huge help. The horizontal component seems like a red herring when it comes to water. Any advantage you might get from the smaller vertical component would be totally overridden by the horrible death you would suffer due to damage to your internal organs.

zubspace 7y ago

Your best bet would be to hit the water like a needle because you can't reduce the vertical velocity in any meaningful way without a wingsuit. The chance is high that you'll break an arm or leg and lose orientation underwater, so be prepared. Maybe its better to keep your arms straight up but thats just a guess because I never tried. You will probably also need to stick around for a long time until help appears. Good luck! There's a fascinating story about a fighter pilot named Judkins [1] who survied a free fall above the ocean. There are other similar stories [2]. A lot of luck involved each time. [1] https://news.ycombinator.com/item?id=15480334 https://news.ycombinator.com/item?id=15480334 [2] http://www.greenharbor.com/fffolder/amazing.html http://www.greenharbor.com/fffolder/amazing.html

achikin 7y ago

There was such a case in Russia several years ago. An experienced skydiver was filming his friends and fell out of a helicopter without a parachute. He has landed in a pond and died immediately. It was said that the impact was so hard that it has torn off his jumping suit.