From how far up can you safely jump into water?

MythBusters did this.
If I can find the link, I’ll come back.
Edit: All I could find was the hammer being able to break the fall and save you myth. That was busted. As for the height, I’m not sure.

It sorta depends.

Are you looking for “generally survivable” or “can be survived”?

A very small % of the people who jump off the Golden Gate bridge survive—I think roughly 1:1000 or so is the ratio, that’s 220 feet (67m).

From the wikipedia article on Diving:

Points on pool depths in connection with safety:

* most competition pools are 5m deep for 10m platform and 4m deep for 5m platform or 3m springboard. These are currently the FINA recommended minimum depths. Some are deeper, eg 6m for the diving pit at Sheffield, England.
* diving from 10m and maintaining a downward streamlined position, results in gliding to a stop at about 4.5 – 5m.
* high standard competition divers rarely go more than about 2.5m below the surface, as they roll in the direction of the dive’s rotation. This is a technique to produce a clean entry.
* attempting to scoop the trajectory underwater against the rotation is extremely inadvisable as it can cause serious back injuries.
* hitting the water flat from 10m brings the diver to rest in about 1 ft. The extreme deceleration causes severe bruising both internal and external, strains to connective tissue securing the organs and possible minor hemorrhage to lungs and other tissue. Very painful and distressing, but not life-threatening.

So 10m (30+ feet) is generally survivable, as long as the water is deep enough.

Looks like cliff diving tops off at about 30m (100ft) – “The speed of a diver from a 30 metre cliff is estimated to be only about 90 km per hour. This is only one-third or so of the terminal velocity.”—http://www.theregister.co.uk/2006/10/20/the_odd_body_cliff_diving/

So I’d go with a skilled diver could do 30–40m and generally survive. Unless you’re terribly unlucky, just about anyone could do 10m and at least survive.

Over 40m it comes down to luck, with a decrease in survival as you increase in height. With no apparent limit including terminal velocity. Just very very unlikely.

I guess the trick is knowing at what speed do you begin to break bones when you hit water. Swimming gets a lot harder with 2 broken legs, but you might still survive. The only way to find the answer to this is to start tossing chimps off of cliffs. I will begin writing the Grant request immediately!

Unless you are trained to jump from up high, I don’t think you would survive jumping from above 100 feet. There are divers who can jump from about 80–100 feet. I saw one guy who jumped from 70 feet up into 10 feet of water and set a world record for it. TWas crazy mon, crazy.

What about cliff divers? we saw a man in mexico who was on our boat do it. Wow!