UKH

What is sufficient depth of water at the base of a DWS if you are 5m, 10m, 15m, 20m or 30m above the water? I'm interested to hear from people who have some experience in the area as I basically have none.

Would also be keen to hear from anyone who has fallen into water that wasn't deep enough. How high was it from and what depth was the water? When you hit the bottom, did you come up with bruises/sprains/cuts etc. or is the impact enough to do serious damage?

There was a thread a few years ago about armchair landings which discussed this a bit I think.

https://www.slatergordon.co.uk/media-centre/blog/2015/08/spinal-cord-injuri...

I expect there may be differences between falling and jumping, but not having deep and clear water below is definitely not good.  

I'm not sure at 30m up I'd want to fall off any more!

Some of the dws at Portland is mid/high tide and over - I typically assume that above about 1.7m on the easytide website it is becoming ok at Cave Hole where there aren't specific protruding boulders. At a low spring the boulders are barely underwater from memory. Which suggests that c5m maybe needs 2m or 2.5m?

I've never hit the bottom hard. Obviously if you're trying to squeeze in a last go when the tide is dropping away what happens is you just touch the bottom gently first and I guess if you don't stop when that happens you'll gradually hit harder and harder.

varies a lot depending how you fall and land. how about 10meters into less than 1m?

youtube.com/watch?v=6A1oCsPM7pw&

You could get stories of people falling from well over 10m into a couple of meters and getting away with it through luck/judgement, but this won't tell you that you won't break your legs if you do the same but are less lucky.

A bit of swell and that rock that  is 2m down could esily be 1.7m down or 2.3 down 5 seconds later.

For  me it's not something I want to take risks with, easy enough to get tide times, know the difference between spring high tide and neap high tide. You can get more than 1m extra water at spring high tides at portland and 3m extra in pembrokeshire compared to neap high tides.

Don't push it, plenty of routes have decent depth, save the dodgy ones for spring high tides if you really want to do them.

I get nervous in a controlled jump from anything above 10m, I wouldn't consider jumping from more than 15m, even into deep water although some people enjoy it and don't seem to hurt themselves (often).

I won't jump anywhere risky and I'm very cautious but I love the feeling and definitely enjoy it.  

5m or 15ft is about as deep as you will ever go from any height, it might not be fun though  

That's pretty hilarious. I laughed hard. And I'll bet his bruises from a bellyflop from that height must have been spectacular over the next few days! I do wonder if there are extra tricks there not being explained, like the snow mountain under the pool actually being the real cushion and the force at first instant being transferred through the water and into the compactable porous solid of the snow before the water deforms to further absorb impact.

I guess my take-home from this is basically to try and hit the water as badly as possible!

To give some further info: I know how deep the water is and exactly what is on the bottom and I would be keeping a close eye on weather and tides and only attempting when the tide is high and the swell is negligible (the latter being most of the time, fortunately). My thought process is definitely more "soloing" because, as AJM said, a fall from 30m into water would be very unpleasant, even if it was deep. The route is hard enough that if it was land underneath, I wouldn't attempt to solo it.

This isn't so useful because it doesn't give anything beyond the obvious (that jumping into water that is too shallow is bad).

I think 2m would be the minimum for any height really because your body isn't far off 2m tall and it seems like you would always want to be falling into water you can't stand up in.

If you're landing in a pencil, yeah that sounds sensible. If you're back-splatting off some sort of fairly low roof traverse you might be able to push the boundaries further.

I recall one day last summer where the last persons attempt was heckled by several people basically standing in the water having just fallen off themselves! But they were all falling off from fairly low down at that point and I'm not sure what they'd have done if they got through the crux!!!

How deep is the diving pool at the swimming baths?

About 3m or 10ft?

5m deep for 10m dive

As others have said it really varies. A bit like highball bouldering where you can get away with falling from a long way up and be fine, but equally you could hit a rock under a pad and snap your ankle from a meter up.

In normal circumstances you want about 3m of decent water underneath you from 5m or above (and even then you could easily touch the bottom if that's what you were trying to do). If you've got less than that you're in to special measures.

I think there's roughly two things you can do: stuff before you enter the water and stuff you can do after you enter the water. Before you enter the water is about increasing your surface area so there's more resistance when you hit the water. I'd definitely recommend spreading your arms and and slapping the water if you're low on depth, it'll sting but won't be that bad. Opening your legs just a touch can also be good. Going full arm chair is a last resort, be prepared for a salt water injection and some John Wayne walking. The arm chair also has the significant disadvantage that if you do hit anything under water it's likely to be arse first which is bad. In theory a bellyflop would be great for limiting depth, but chances of sticking it are about 0 and most likely you'll give yourself some sort of heinous back problem.

On to the second category: in the water. Generally you'll only do this stuff if you've got a decent amount of water to work with. Tip number 1 is to starfish out once you're submerged, this is generally a decent idea anyway as it'll stop you going too deep. This is mostly in the arms as you dont want your legs going all skewif. Another technique you can use is to sort of 'fold' once you're under water a bit like this  youtube.com/watch?v=CS8_5ogRFpQ&t=123 but legs first obviously. This helps limit how deep you're going, though you trade some depth for some horizontal movement so not great if you're close to some rocks. Be careful with the depth too, as with the arm chair you end up going a bit bum first which is bad news if you do hit anything.

What's on the sea floor is also an important consideration. You can hit a sandy floor pretty hard and be fine but if you hit a janky reef or a pointy boulder with any sort of speed it's easy to hurt yourself.

In terms of height, up to about 10m most of this stuff will work pretty well. Up to 15m you can use these techniques but it's going to sting, still worthwhile though imo as it'll be less painful than a twisted ankle or broken leg. Above that you basically only want to be jumping in to deep enough water, typically 4m+. If you're arm chairing from 15m+ you've f*cked up, and at best it's going to really sting for a couple of weeks.

If you're going in from 30m and up anything less than a perfect entry is going to really hurt and could end up in hospital without trying too hard.

50ft over 12ft pool. Whether nature will provide that is another matter.

https://www.redbull.com/us-en/psicobloc-climbing-2014-video

That's great. Thanks for all the info.

I think there is 4-5m depth on the highest high tide but I can check that out easily enough with a wee swim and a weighted rope. I'll do some measuring to see how high the crux is too. It's easy enough to think something feels like about 10m up and actually it's 15m so worth a good check.

It's rocks on the bottom.

Nice! They are going to be erring on the side of caution here too if it's a comp, so based on that, it seems likely that one could fall 20m into 4m of water without too much of a worry.

Speak for yourself, I'd be very worried!

4m doesn't seem enough.  Diving pools are at least 5m and that's not from 20m.  

Looks like there is some sort of mattress under the paddling pool. However I'm still impressed!

I'd imagine that you would go deeper in a dive than a jump, though, and head first at that.

This is true. But they are made with the idea that you will a) be going in headfirst and b) be perfectly streamlined so you cut through the water and c) will have been designed by a very safety conscious person somewhere with a design specification that says something like "pool must be at least 150% of max depth a person could possibly reach with a perfect pointy dive" or something like that.

You don't want a harsher impact with the surface of the water but you do want to increase resistance at depth by increasing the inertia or viscosity of the fluid at depth.

The obvious solution is to sink a 1m layer of liquid custard onto the seabed.

It's possible to get to the bottom from 10m and 20m is much higher.  

Custard is a silly idea.  Cornflour is much better

Absolutely, I'd go for custard every time, a quick underwater meal would go down a treat (pun intended).

For sure, but if you want to touch the bottom of a diving pool from 10m you have to try and do it, whereas if you're jumping off  while DWS most things you'll naturally do will limit the depth you'll go to pretty effectively.

Interested would having a little swell to break surface tension be advantageous from a higher entry? Or is it all pretty negligible if you have a good entry

I wish it was me that suggested the custard - or indeed the cornflour - but it seems I accidentally posted a blank message.  I like the patisserie turn this thread has taken and I'll come back to that, but I was first going to reply to the OP with some torte-free experiences:

The lesson I've learned the painful way is that if you jump off anything more than about 10 m high, don't try any of the things suggested in previous posts to reduce your penetration into the water unless it's really shallow and you know are going to hit the seabed so hard that the injuries you may incur hitting the surface of the water are worth it.   Much better, when you jump/fall from more than 10 m up, is to point your toes, keep your arms locked by your sides and use as much water depth as you can to slow you down.  

I've jumped from 20 m without hurting myself.  I found it scary, and, from what I could estimate, I went about 6 m deep with a feet-first 'standard' jump: pointed toes, straight legs and back, arms locked to the side anddon't look down at the last minute to keep from tipping forward.  From that height, you are travelling at over 60 km/hr - too hard to slap the water, sit on it etc without getting hurt.  But don't take my word for it:

https://www.climbing.com/skills/learn-this-deep-water-soloing-101/

Armchair entry

This is the default position for shallower water (<10 feet), to limit deep entry; it should not be used in long (and faster) falls. With this technique, you pull your legs up toward your chest and lean back as if sitting in a lounge chair, with your arms extended to your sides. This method is difficult to master, but dramatically decreases impact by letting you contact the landing zone with more of your body. Performed correctly, an armchair entry can absorb a 30-foot fall in as little as 5 feet of water."

As for depth of water: The World High Diving Federation considers water depths of 13 to 15 m safe for dives from 20 m. So, even feet-first, the suggested 4 m depth in a previous post is pushing it a bit...   Can you really decelerate safely from 60+ km/hr to zero in less than 3 body-lengths?  I know through experimentation at lower heights that I can't - not at risk and pain levels I'm not prepared to accept. But we all have different thresholds, so practice and find yours.

I suggest carrying a can of squirty cream in a quick-draw holster, and coating your landing area with a thick layer of cream just before you hit the water.  With the surface cream layer, and the deep-custard layer, try to relax and turn to jelly on impact. Then, your High-ball deep-water solo will be a mere trifle.

Yes, swell and waves do help with absorbing some of the force of impact - but that means you also need more water depth to slow down.  I don't know how big these effects are, but from height, they can probably make a difference - the cliff-divers seem to think so:

https://adventure.howstuffworks.com/outdoor-activities/water-sports/cliff-d...

youtube.com/watch?v=ZDqN8sEl6oE&

172 ft dive, enters water feet first.

https://www.wired.com/2011/03/professor-splash-world-record/

 Taylor recently ventured to frigid Trondheim, Norway, to once again try to break his own world record and jump from 36 feet up into a pool with only 1 foot of water. It would be his 13th career world record. "The real big trick with this dive," Taylor told the BBC before the jump, "is to land flat and try and get as much water out of this pool as I can. I want to dissipate as much water for a cushion effect." He may have used protective clothing. Provides link to a Tokyo video.

PS Not advising any of this. 

I'd be happy with 4m to a sandy bottom, or a big rounded boulder, without much of a swell, from 20m, but I would never say falling from 20m was not a worry. I've knocked myself unconscious landing on my back from about 10m on a flat water day, and if the swell is enough to make the water soft, you probably want at least 5m depth to compensate.

A pedantic point, but I think quite important - it's actually a bit of a myth that surface tension is significant.  The thing is that water is quite heavy and has inertia - breaking through the surface as you enter the water isn't the problem, it's moving water out of the way as your body pushes in.

The thing about 'white water' generated by waves or whatever isn't that the surface has been broken up, it's that the water has been aerated - it's full of bubbles of compressible air making the water less dense and also more 'squashy'.  Like a thin soft bouldering mat on a hard floor, I think it would be a mistake to expect a wee bit of foam on the surface to make much difference.

Out of interest, what happened next? Dragged out by friends?

From memory of my youth, diving boards in swimming pools were ~3m deep for 5m boards and 5m deep for 10m boards. Would assume you'd go a lot shallower falling flailing on your arse than diving like an Olympian. 

If you go down a wormhole on youtube you can find videos of shallow diving. Think the record is a foot of water from 12m up...

In conclusion, there is no right answer. 

Just remembering back to my diving lessons on 1m, 3m and 5m boards, it can bloody sting if you hit the water wrong. Not allowed in public sessions, but in lessons, we were allowed/encouraged, to wear rash vests with a high neck to take the sting off - I wore one that's 1mm neoprene front and back with Lycra collar and sleeves and was pretty glad of it a couple of times.

My worst injury, though, was mucking up a somersault, hitting the water still tucked and putting my teeth through my lower lip when I bit my knee, which put me on a diet of soup for a week.

Just to digress a bit, don't underestimate cold water shock, hypothermia and drowning as other risk factors once you're in the water, especially if injured as a result of getting there, and make sure you have a safe exit route.

I think it's generally accepted not to climb wearing a buoyancy aid - can cause more issues when hitting the water. My wife bruised her ribs quite badly as a result of a badly fitted PFD riding up after quite a small jump on a coasteering team building trip.

Have someone ready to throw you a float/line - you'll be trying to swim with pumped arms!

Any swell mentioned above might be beneficial to your landing, but not if it then slams you into the rocks/cliff while you're trying to get out.

If you/someone else gets into difficulties in the sea, dial 999/112 and ask for the coastguard.

Check this out for "inspiration":  youtube.com/watch?v=1qTCoVIgY9Y&

There's another film of him leaping from The Prow in Vivian Quarry, plus lots of other stuff.

I once fell from about 6m and hit a turtle. Think he was approx 2m down...

Came to about 5m down, totally winded and after a quick check my limbs were all working  started swimming up. When I got to the surface it was remarked that I had been down for rather a long time, but nobody had yet thought to dive in.

Made me a lot more careful about just turning up solo at a popular DWS spot and assuming those around would have the common sense to look after each other!

That's quite a scary thought really. Whenever I've DWS'd I've done it with someone else present which gives you a sense of security, thinking that if anything goes wrong then they can fish you out.

But thinking about it, the normal thing to do when someone goes in is to wait for them to come up. And then if they don't come up, everyone just looks around at each other waiting for someone to act, by which point it's too late! And if they're not wearing a mask, how are they actually going to find the person who's sinking?!

Makes me think that what should happen is to have a mask at the crag which is passed between the spectators for someone to wear on top of their head when not climbing. As soon as someone goes in badly, the person with the mask pulls it down and dives in, whether or not they know that help is needed. Anything less and it'll be too late to act by the time it's apparent that help is needed. By having a mask at the crag and passing it round, it's then clear who is the person who should be jumping in, rather than everyone looking at each other waiting for someone else to take action.

Do a lot of people drown when DWSing? I didn't know this was a major thing in the sport, but to be fair I also don't know anyone who is really into DWSing.

Turns out it's 22m from the top of the route to the water and on a good high tide I can expect 4.5m of water depth (4.9m if it's a spring tide) and the cruxes are not at the top of the route, so it seems fairly safe (except that obviously it's going to hurt like hell when you hit the water as several people have said.

No idea what the numbers are. I've heard a number of stories of people going out alone and not coming back and also the occasional incident when people have died when other people were at the crag/in the area. I think one example I'm thinking of sounded like cold water shock which then meant they couldn't climb the hauling out rope and didn't make it on the short swim round to the alternative exit.

22m is pretty high - "fairly safe" sounds about right but it can do a lot more than "hurt like hell" if you land badly from that height. If you hit the water well, with climbing shoes on it shouldn't hurt.

Worth getting plenty practice falling and water entry before you commit to topping out.

One of my DWS partners likes to swim though tunnels 5m or more down unaided. I always feel emboldened to go for it when he's around 😁

Great idea, but don't ever "dive" with a mask on - they're not designed for it and could break really badly. Either jump in, or wrap it round your arm for the dive and put on when in the water.

I'll have company, going alone would be more foolhardy than I am. I'm confident that getting out after a fall shouldn't be a problem.

I'm not looking at a route in the Med though

I can't say for sure, but I'd assume there's a high probability.

There's the very sad story of one of the Cook brothers (from the family who did a lot of the early DWS development around dorset) who went DWSing in Mallorca on his own and didn't come back. There's a memorial plaque at the top of connor cove.

I know of a few close calls too. A friend of mine was DWSing on his own and passed out under water. Fortunately he came too and managed to swim to safety.

There's another friend I know who pulled a hold of very high up and smashed himself up pretty badly before hitting the water. Fortunately he was with a couple of other very experienced chaps who managed to get him out of the water and to the hospital.

All a bit grim, but on balance I'd try not to let it put you off. In many ways it's no different to most climbing: there's definitely risks involved but you can do a lot to manage the risks e.g. climbing with other people, rigorously checking water depth, spending some time learning to fall off and so on.

If recommend wearing a wetsuit, or waiting until the sea is warm enough, and getting plenty of falling practice in before venturing up to 22m. 

It's more than high enough to put you in a wheelchair or a pine box.