# I am contemplating a high jump into water. **URL:** \ **Category:** Factual Questions\ **Created:** [March 5, 2014, 6:45pm UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953 "2014-03-05T18:45:18Z")\ **Posts on this page:** 19\ **Page:** 3
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [March 7, 2014, 8:08am UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/41 "2014-03-07T08:08:05Z")
> [@ducati](#): > > We would spread our legs and arms just after impact to lessen the depth we’d go, because you just don’t want to be 40 feet down and have to swim up. There were a couple of times where I thought I just wouldn’t make it back up, even though I could see people up above me. The water was so clear, it was easy to misjudge your depth. I’m pretty sure you are misremembering. Even with a perfect entry you wouldn’t get anywhere near 40 feet down. I’ve jumped off of bridges over the intercostal canals a lot and never went down more than 10 feet or so. To the OP, cross your feet at the ankles to protect the jewels (this is from painful experience), keep your elbows tight to your sides and cover your face with your hands. This will keep your chin from taking a whack. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [March 7, 2014, 12:12pm UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/42 "2014-03-07T12:12:52Z")
> [@White SIFL](#): > > I’m pretty sure you are misremembering. Even with a perfect entry you wouldn’t get anywhere near 40 feet down. I’ve jumped off of bridges over the intercostal canals a lot and never went down more than 10 feet or so. I’ve heard 1/2 the drop distance is what you would like underwater. I do remember on some high jumps looking up at the surface and other swimmers from below. It does seem far but I think part of that is due to refraction, and the other part is due to time to overcome inertia and water resistance from your stop and start noticeably heading up under your own power. By putting them together it seems logical that the mind would place you ‘deeper’ then you actually were. ---
**Author:** ![BetsQ](https://avatars.discourse-cdn.com/v4/letter/b/fbc32d/32.png) [@BetsQ](https://boards.straightdope.com/u/BetsQ)\ **Post date:** [March 7, 2014, 7:14pm UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/43 "2014-03-07T19:14:54Z")
> [@White SIFL](#): > > I’m pretty sure you are misremembering. Even with a perfect entry you wouldn’t get anywhere near 40 feet down. I’ve jumped off of bridges over the intercostal canals a lot and never went down more than 10 feet or so. > > To the OP, cross your feet at the ankles to protect the jewels (this is from painful experience), keep your elbows tight to your sides and cover your face with your hands. This will keep your chin from taking a whack. I’m skeptical about 40 feet, but I’m also skeptical about not going more than 10 feet. As a competitive diver, I found that it wasn’t difficult to touch the bottom of a 16’ pool when going off the 3 meter, and I’d have to actively avoid the bottom of a 14’ pool. ---
**Author:** ![repairminded](https://avatars.discourse-cdn.com/v4/letter/r/958977/32.png) [@repairminded](https://boards.straightdope.com/u/repairminded)\ **Post date:** [March 7, 2014, 8:24pm UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/44 "2014-03-07T20:24:19Z")
Since you are most likely past the age of procreation, I see absolutely no downside if you choose to take this totally unnecessary risk of removing yourself entirely from the gene pool. ---
**Author:** ![Chief\_Pedant](https://avatars.discourse-cdn.com/v4/letter/c/a6a055/32.png) [@Chief\_Pedant](https://boards.straightdope.com/u/Chief_Pedant)\ **Post date:** [March 8, 2014, 12:16pm UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/45 "2014-03-08T12:16:06Z")
Given all the personal experiences being posted, I’ll just reiterate my earlier that this is an old, fat guy. There is no parallel between his chance of surviving this injury-free and a youngster of normal weight with young musculoskeletal integrity doing the same thing. Not only will the deceleration deformation forces be much higher because he’s so fat; the ability to withstand those forces is substantially diminished, and the ability to heal from them is further reduced. His abdominal panniculus alone being pushed up into his abdominal cavity could easily rupture his liver, for example. But if he does try it, I hope it gets on YouTube with a link back here. ---
**Author:** ![ChickenLegs](https://avatars.discourse-cdn.com/v4/letter/c/ecc23a/32.png) [@ChickenLegs](https://boards.straightdope.com/u/ChickenLegs)\ **Post date:** [March 8, 2014, 4:37pm UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/46 "2014-03-08T16:37:20Z")
I jumped off a 50’ cliff at Dale Hollow when I was 18. Water went up my ass. Had the wind knocked out of me, and if I hadn’t been wearing a life jacket, it might have been a bad thing. Back then I was a 135 pound rippling mass of teenage muscle. I’m 48 now. If I did it again, and was betting, I’d bet on “death” or “serious injury”. Probably death, if I got good odds. ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [March 8, 2014, 5:30pm UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/47 "2014-03-08T17:30:05Z")
> [@Chief\_Pedant](#): > > Given all the personal experiences being posted, I’ll just reiterate my earlier that this is an old, fat guy. I also want to reiterate that this isn’t a jump from a cliff into a lake with relatively easy access. This is into a hole with a presumably 18 m climb out. That takes things like a broken leg or dislocated shoulder from painful to deadly. ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [March 9, 2014, 5:33pm UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/48 "2014-03-09T17:33:42Z")
> [@harmonicamoon](#): > > Close to where I live is a cenote. From ground level to the water below is 18 meters. The depth of the cenote is 160 meters. So hopefully I won’t hit bottom. My calculus days have been forgotten. I would like some answers, so I have fewer unknowns before attempting this action. I am 65 years old, a good swimmer and weigh 120 Kilograms. If some of you math/physics folks could help with these questions, I would appreciate it. > > 1. How is the best way to enter the water? I am not planning on a swan dive. Going to enter feet first. I have done some jumps, and when I entered with feet flat it stung. So, I am thinking to point my toes downward. Or, would it be better to wear shoes? > > 1a. Should my arms be straight up over my head? I am thinking that a smooth entry would be better, right? > > 1. How many seconds will I be flying? Before entering the water? > > 2a. Speed upon impact? > > 1. What would be the maximum depth of my penetration in the water? > > 2. Is there other information I should know? > > For math folks and others, this question. > > 1. Is this a really dumb thing to attempt? > > Thank you for your time and your calculations. At 265 lbs and 65 years old unless you are 6’7" or taller and in absolutely amazing shape you are WAY too fat (and old) to do this safely. This is one thing that needs not to be on your bucket list unless it’s the very last thing you intend. I speak as a 6’3" 55 year old man in relatively good shape who has been at and over that weight. This is NOT like a fat teenager doing this. If you get injured you will not heal quickly and may be maimed permanently. There is a 50/50 chance you can complete it OK but one thing out of alignment and you are doubly screwed due to your age and weight. For someone your age and weight this is sheer stupidity. ---
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [March 10, 2014, 6:21pm UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/49 "2014-03-10T18:21:23Z")
> [@kanicbird](#): > > Breath out before the jump and in on the way down- too long to breath in before. Huh? First, two seconds is too long to hold your breath? Seconds, this could be pretty bad advice based on my experience. I’m scared stiff by falling (which is why I love to do it). The first time I jumped more than say 20 feet I discovered that the term “scared stiff” is literally correct. When I finally managed to trick my body into stepping off the ledge my arms went up. On the way down, I tried to pull my arms down to my sides and was unable to, since all my muscles were firing on full. I doubt I’d have been able to take a breath, either. I’d far rather have a full lungs than empty ones. > [@ducati](#): > > No matter where you are geographically, the water temperature is going to drop significantly after 10-15 feet, to about 50 or 60 degrees. It will surprise you. I’ve been plenty of places where the water is 80 degrees from just under the surface to nearly 100 feet down (scuba diving). I’ve swum in the clear waters of Crystal Creek in FL, which isn’t very deep, but is the same temperature throughout – since it’s flowing water, there are no layers. There may be holes with cold layers at the bottom, but I didn’t notice any. > [@Son\_of\_a\_Rich](#): > > This post triggered a really old memory of a scene in a Batman story. BM and Robin were high above water and their only recourse was to jump. They found some tires, and tied them with a length of rope to their ankles such that the tires would hang down below them and break the surface of the water. I always wondered if that would really work. Silliest thing I ever heard. I would expect the tires to hit the water last, and that would probably be the least damaging outcome. ---
**Author:** ![harmonicamoon](https://avatars.discourse-cdn.com/v4/letter/h/65b543/32.png) [@harmonicamoon](https://boards.straightdope.com/u/harmonicamoon)\ **Post date:** [March 19, 2014, 2:11am UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/50 "2014-03-19T02:11:13Z")
Thank you for your calculations and the experiences you have related. My initial fascination was the free fall experience. But when I learned it would only be 1.9 seconds, it surprised me. I wanted more. My other thought was, I am just gonna land in water. No big deal. Then you folks told me I would hit it at 45 MPH, and some of you related experiences. It was then that I understood that water isn’t so soft. Thank you for sharing your wisdom. Ignorance fought. I ain’t gonna do it. ---
**Author:** ![j\_sum1](https://avatars.discourse-cdn.com/v4/letter/j/8baadc/32.png) [@j\_sum1](https://boards.straightdope.com/u/j_sum1)\ **Post date:** [March 19, 2014, 5:39am UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/51 "2014-03-19T05:39:18Z")
Go anyway. Throw a big rock. It will make a nice splash which is kind of gratifying. You might even feel the spray. Then sit back and enjoy the beauty of the cenote. ---
**Author:** ![chacoguy](https://avatars.discourse-cdn.com/v4/letter/c/50afbb/32.png) [@chacoguy](https://boards.straightdope.com/u/chacoguy)\ **Post date:** [March 19, 2014, 6:40am UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/52 "2014-03-19T06:40:02Z")
Hire some guys to throw you out of an airplane. It’s expensive; but you will never forget it. ---
**Author:** ![Bumbershoot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bumbershoot/32/3428_2.png) [@Bumbershoot](https://boards.straightdope.com/u/Bumbershoot)\ **Post date:** [March 19, 2014, 11:36am UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/53 "2014-03-19T11:36:40Z")
I normally would encourage just about anyone to jump out of an airplane, but at 120 kg the OP may have difficulty finding a dropzone with a parachute big enough for him. Most DZs have a weight limit of approx. 100 kg. If he wants to experience freefall that’s the way to do it, but he might have to call around to find a DZ to accommodate him- and then travel a fair distance to get there. ---
**Author:** ![Dead\_Cat](https://avatars.discourse-cdn.com/v4/letter/d/9fc29f/32.png) [@Dead\_Cat](https://boards.straightdope.com/u/Dead_Cat)\ **Post date:** [March 19, 2014, 12:39pm UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/54 "2014-03-19T12:39:50Z")
If you just want a freefall, then a tandem skydive (long) or bungee jump (short) should both be a lot safer. Not _safe_, necessarily, but certainly _safer_. Please note I am not an expert in any of these disciplines. ---
**Author:** ![Learjeff](https://avatars.discourse-cdn.com/v4/letter/l/94ad74/32.png) [@Learjeff](https://boards.straightdope.com/u/Learjeff)\ **Post date:** [March 19, 2014, 11:16pm UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/55 "2014-03-19T23:16:42Z")
There is a much better way to experience free fall. It’s called skydiving. You don’t get much freefall at first, but you can work up to it. And who knows, maybe these days there are tandem freefall jumps for beginners. ---
**Author:** ![Bumbershoot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bumbershoot/32/3428_2.png) [@Bumbershoot](https://boards.straightdope.com/u/Bumbershoot)\ **Post date:** [March 19, 2014, 11:43pm UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/56 "2014-03-19T23:43:58Z")
> [@Learjeff](#): > > There is a much better way to experience free fall. It’s called skydiving. You don’t get much freefall at first, but you can work up to it. And who knows, maybe these days there are tandem freefall jumps for beginners. There definitely are tandem freefall jumps for beginners, and there are other teaching methods besides static-line progression as well- methods that allow a person to experience freefall from the first jump. Accelerated Free Fall (or AFF) is one such method. However, as I pointed out in post #53, most skydiving centers don’t have parachutes big enough for someone weighing 120 kg. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [March 20, 2014, 1:30pm UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/57 "2014-03-20T13:30:14Z")
There are also those indoor free-fall rides with a huge fan under the base. It might not look like free-fall but the wind/weightlessness feeling is basically the same. ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [March 20, 2014, 4:51pm UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/58 "2014-03-20T16:51:21Z")
> [@ftg](#): > > There are also those indoor free-fall rides with a huge fan under the base. It might not look like free-fall but the wind/weightlessness feeling is basically the same. You might need to lose a little weight for those, though. The one in Seattle has a cut-off of 250 pounds if you’re over 6 feet, and 230 pounds if under 6 feet. ---
**Author:** ![Buck\_Godot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/buck_godot/32/6573_2.png) [@Buck\_Godot](https://boards.straightdope.com/u/Buck_Godot)\ **Post date:** [March 21, 2014, 9:08pm UTC](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953/59 "2014-03-21T21:08:52Z")
> [@j\_sum1](#): > > Go anyway. Throw a big rock. It will make a nice splash which is kind of gratifying. You might even feel the spray. Then sit back and enjoy the beauty of the cenote. Or drop down a watermelon… Seeing the results will probably make you much happier about your decision not to go yourself. 😃 [Previous page](https://boards.straightdope.com/t/i-am-contemplating-a-high-jump-into-water/682953.md?page=2)