Comment by NateEag | Hacker News Reader

Comment by NateEag | Hacker News Reader

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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.

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.

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

Ah, makes sense. Thanks for the info!

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?

I think you completely missed the horizontal part of the question.

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.

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