Watching the 10m platform diving on the Olympics got me to wondering: if you had to jump into the water from a significant but survivable height (cruise ship deck, etc), what is the safest way? Or at least, what maximizes your chances of surviving it?

I figure some of you Navy vets will know.

Don’t jump into the water if there are sharks.

Clench. The water is known to "enter with force" from heights.

cross your legs and cross your arms over your chest and jump feet first. I would suggest that you have a life vest on and the straps that go around your crotch are tight or the vest will leave you when you enter the water.

I dunno.

I was taught to swim from the airlock to the surface saying "ho ho ho ho" all the way up to prevent rupturing a lung.

No jumping from a submarine.....

I always pulled both legs way up close to my chest, wrapped my arms around the bent knees, and yelled "CANNONBALL!!!"

Without question, feet first.

Years ago I was on our high school swim team and competed as a diver. I still recall how painfull a slightly off-vertical dive from a 5m springboard could be -- I can't begin to imagine screwing up from a 10m platform.

Jim

How many feet does it take for a person to get up to terminal volecity,126 mph? After that point it doesn’t make a difference how many feet the drop is, does it? You reach your maximum speed and that’s it.

I can understand wanting to get out ahead of time, you don’t want to get sucked under with the ship. But I would try to make the drop as little as possible.

Yes, DO CROSS YOUR LEGS!

Besides having the feeling of being kicked in the ba*ls you will get a high power enema. It is a VERY violating feeling and uncomfortable. (Yes that is experience talking).

I'd recommend jumping with your shoes on as the impact is substantial over 25 feet. Assume you are going to hit the water at any instant. Most people don't get the timing right the first few times. Stunt men use a bubbler that serves two purpose 1)It helps them to clearly see where the water is below (compensates for depth perception issues) and 2) lowers the surface tension of the water (so the water doesn't impact as much).

In a survival situation, cross the legs, cross the arms and keep ensure your face FOLLOWS your body. I'm not an expert! This is just what I've learned from quarry jumping.

-NIM

Please don’t give any more info on this, that was more then enough!

Good comments all, and I agree. I have vertigo when going down feet first, and get off-camber. Try a nasal wash at 20 mph....

I was a lifeguard during summers in college, and used to practice diving - no instruction, form was lousy, but had a lot of fun. All off a 3 meter board Then i finally got the chance to try platforms. I tried the 5 meter first, to try and get the hang of it. It was basically like the 3 meter, but more of a rush - a lot of fun. Then I dove off the 10 meter. Nothing fancy, just a dive. I entered cleanly, and was shocked at how violent the impact was. It was much more than twice the 5 meter... I might try it again, but without instruction, once was enough.

Remember, 32 feet per second per second (9.8 meters per second per second). So you're basically doing 33 mph off a 10 meter platform.

Given the violence of the 10m impact, I wonder what everyone thinks a survivable height is. I don't think I'd want to go much higher without a chute.

The old Navy method was to
Drop feet first toes pointed
Cross legs at the ankle
Cross arms
Grasp opposite shoulders
Tuck chin into chest
Keep elbows tight
DO NOT repeat DO NOT wear life jacket
Grasp a strap to the jacket

You might be able to wear an inflatable style life jacket

Crossing the ankles keeps the impact from spreading the legs and breaking them. This minimizes the the impact on sensitive areas. It also reduces the risk of hydraulic impingement to lower body openings. Yes the entry can cause internal organs.

You want to be as streamlined a package as possible. You want to pierce the water as cleanly as you can. Not land splat. Cannonball dives don't work. At any significant height it is like hitting concrete.

You hold onto the life jacket. Yes when you hit the water you will lose it. But it should be near when you resurface. The jacket is bulky and meant to float. It will stay at the surface. If you are wearing it even or especially with crotch straps it will greatly magnify the impact. It will try to keep you at the surface and remove your head in the process along with other body parts. There will be no give such as a chute opening in skydiving.

Although things may have changed in 30 years since I learned how.

Raspy:
I stand corrected, thank you.

I went through the basic course about 3 years ago, and it's essentially unchanged. I think they've added "Clench buttocks" and "pinch nose" to the routine. But, good advice on avoiding the enema and nasal rinse.

NO LIFE VEST. He's not kidding - remember, they're designed to keep you afloat, with your head out of the water. Often with a substantial neck portion. Guess what part likes to break around that collar?

I don't know the right way, but a former acquaintance jumped off this bridge into the water, 100' below. Somehow he lived, but he had bruises all over his body. As I recall, he said that he did cross his arms and legs, and did wear shoes. I didn't think to ask him if he got an enema from it.
http://en.wikipedia.org/wiki/Pennybacker_Bridge

He was prompted to jump after learning that someone died jumping from it.

We have now had a couple of deaths in the UK from kids and a new craze.

Google TOMBSTONING

Also have a look at

Tombstone Safety

Terminal Velocity when in a maximum drag position (spread eagle) is roughly 124mph. If you are upright, it increases to about 200mph. It takes roughly 5.7 seconds of falling to reach 124 mph, during which you fall about 530 ft.

FYI, acceleration due to gravity (9.81m/s) is considerably faster than a Ferrari.

My math may be off, so feel free to correct me.

"...My math may be off, so feel free to correct me..."

Sounds close enough to me. Doing math gives me a headache...

Hi Glock-A-Roo

http://www.youtube.com/watch?v=xkjDyF1Oss4

I guess we'll just have to ask these kids from Arbroath.

Forget the kids from Arbroath... check this guy out. Do you think he clenched...?

Somewhere I've read that it is normally only possible to survive a jump of about 130 feet into water. Sorry I cannot come up with the source, but it would probably be in the ballpark.