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Technical Diving: How to let the flow go during decompression dives in a dry suit

Long technical dives in cold waters presents numerous challenges, including how to relieve oneself. Trying to solve that challenge can leaf led to a darkly comic moment where you end up talking about your penis size with a stiffly correct woman called Maureen.

SITTING on the bench of the X-Dream boat run by Old Harbour Dive Centre (‘Sea Diving At Its Best’) out of Portland, I began to realise I might have some trouble with this technical diving lark.

“You better have a drink before you dive, you wanna stay hydrated if you’re going into deco,” one half of me argued.

“You’ve got to be careful swigging water, you don’t wanna be caught short underwater,” the other answered back.

Peeing underwater. If I was in a wetsuit it would be no problem, just open up, flow and flush. Yeah, I know you like to screw our noses and pretend otherwise, but we all pee in our wetsuits. All of us. I know someone who even has a particular signal for it.

Wearing a dry suit, though, doesn’t offer the same liberation; no, needing a pee in a dry suit is one hell of a stinkin’ problem … And trying to solve it can lead to a darkly comic moment where you end up talking about your penis size with a stiffly correct woman called Maureen.

Dehydration, the body's response to losing more fluid than it takes on, is a serious condition for any sportsman. For a diver, dehydration is downright dangerous. To put it simply, skipping a glass or two of water before the dive can result in the thickening of the blood and a reduced blood flow.

Blood is responsible for the exchange of gases in the body. If the reduction in blood plasma becomes too great it decreases the efficiency in off-gassing of nitrogen and helium from the body during decompression and may increase the risk of decompression sickness (DCS).

May increase the risk? While it is true dehydration is a known risk factor for DCS, connecting the dots between dehydration, bubble formation and growth, and DCS can be difficult. Field tests conducted by Divers Alert Network (DAN) have found many divers are not well hydrated at the start of a dive. End-of-year reports highlight the problem; dehydration crops up in case files of bends victims. “Drinking the night before diving, may have resulted in dehydration”; “Dehydration could have played a role in this event.”

Staying hydrated before a dive seems a sensible, straightforward proposal then. If we put it in, we just need to find a way to let it out because being submerged in water really does make you want to go.

Divers have tried all manner of solutions. Some do skip that drink before the dive and hope they won't get hit, others just plait their legs until they get back to the boat with a bladder that feels like it’s about to burst. You can spot them instantly. They’re the one's who cast-off expensive kit, shuffle from one foot to another, like a lizard in the sun-baked Sahara, and beg someone to unzip their suits as they hot-foot it to the head below deck.

There are a few divers who use adult diapers. Yes there really is a grown-up version of Huggies pull-ups, and they really can absorb up to 2900ml of liquid. Other divers fit a pee-valve to the inside of their dry suit. It's a length of tubing which is attached to a sheath glued around the particular body part. When they need to relieve themselves, they just go and vent the liquid into the surrounding water via a one-way valve.

A friend of mine had one fitted to his suit. It was great until it imperilled his parental promise. "You have to keep your gentleman clean-shaven," he was telling us as he yanked his dry suit down at the end of a dive. The suit really did reach his ankles before he realised he was still plumbed in and he really did shriek a childlike shriek as he crumpled onto the floor clutching himself. It appears the glue used to hold the sheath in place around your stubble-free gentleman really is that strong.

Investigating alternatives, I heard about a discreet urine collection bag which could be wrapped around my leg. Ignoring the fact it was advertised on a website dedicated to incontinence problems, I called for a sample pack.

The saleswoman, I'll call her Maureen, sounded very prim, the kind of middle-aged woman who had a regal hairstyle, half-moon glasses dangling around her neck from a beaded chain and liked classical music.

“What’s the issue, sir?” she asked.

“I'm a technical scuba diver.”

“Oh, I see. And does urinary incontinence cause you particular problems with your sport, sir?”

"No, err no. It's not a problem, it's when I'm decompressing, you see. If I need to go, I can’t just let it out.” I mentioned a dry suit, but don't think she got it.

“Oh I see sir. And what size sheath will you require?"


“Yes sir.”

Apparently, I had to state the diameter of my penis shaft.

Surprisingly, it's not something I'd thought about measuring before.

Maureen explained sheaths ranged in size from 21 millimetres to 40 millimetres. Holding my fingers about 40 mm apart — I like to use 40 millimetres instead of four centimetres; it made everything sound longer — I suggested I was probably at the top end of the company’s product line.

“Of course, sir.”

A few days later the package arrived (discreetly marked: “Sample Pack. For all of your intimate health needs”). Inside, I found a urine collection bag integrated into an elastic band which was wrapped around the leg. There was a small rubber tube with a plastic nozzle which was designed to be pushed into the end of a sheath. There were six sheaths of three different sizes.

There were two 40mm-sized sheaths. The others were progressively smaller. Packing the box, Maureen might have added a medium sized sheath or two, thinking: “Just in case he's being hopeful.” Then, she went down in size again. “Just in case he’s a liar.”

The freakiest item was the ... erm ... measuring guide. A strip of card about 21cm long, it featured five cut-out semi-circles, small on the left and progressively larger until it reached the largest, a 40mm diameter, on the far right.

“Starting with the largest, place each section of the measuring guide over the mid-shaft …” the instructions stated. And there really was a handy diagram to help you achieve a close fit.

I'm still not sure whether starting with the largest first is a good idea. It’s kind of like a medical version of losing on Bullseye; “Here's what size you want to be …”

“Guessing the size is not accurate and can result in leakage if the wrong size is selected,” the promotional material advised. A buddy of mine once experienced a malfunction when, halfway through a dive, his particular brand of sheath had suffered a malfunction — call it operator error — and he filled his boots. When he walked out at the end of the dive he was still squelching.

I did test the collection bag on a training dive at Stoney Cove. Going through with the procedure of ‘going’ was hard at first; you have to trust the plumbing. When I finally plucked up the courage, I was so happy to have finally found a solution to the drinking problem. I went again and it was such a relief. Too much, as it happens.

I felt the leg bag bulge … and I was still going. It felt as if I had a couple of pounds of pee wrapped around my leg that was about to explode. I clamped myself and waited for the end of the dive. It couldn’t come soon enough. At the surface, I told my buddy I needed to pick up the pace.

I’ve got out of the watering moved sharpish, scuttling from the water’s edge to the car where I’ve shrugged off my kit. And the pressure is building. I’m parked by the filling station and the nearest toilet is all the way over by the pub. Clamping myself with one hand to stop the flow, I scurry off. Waddling with this explosive load sloshing around my leg is awkward, but I’ve got no choice. Across the length of the car park I go, following the row of vehicles that lead to the john; a man with a balloon of pee wrapped around his leg just waiting to burst; doing this crazy scuttle amid divers drinking tea, students preparing kit, excited young children, dogs. There’s a knowing look from some of the divers, they’ve have been through something like this before, they’ve seen the toilet dash and they know there’s no pressing pause. Time is of the essence as I reach the toilet block … and I’ve still got my suit zipped closed across my shoulders.

In the end, I stopped using the leg bag. That’s not because it’s not a great product under the right kind of circumstances, because it is, but a buddy of mine threatened to slap my legs after each dive, like a soldier plunging a blasting detonator, to trigger an explosion.

There is a serious side to this experience, though. As divers, we want to be hydrated before you dive. It’s much better trying to avoid dehydration by drinking plenty of water as part of an organised, pre-dive schedule. You don't want to neck a litre or so just before you submerge, this will only flash-flood the body and head straight to the bladder. To hydrate the tissues, you want to drink smaller amounts at regular intervals.

“The actual take-home message is not to increase plasma volume too rapidly or too much as this will increase urine production and not really hydrate the tissues. My advice is to drink a glass of water every 15 or 20 minutes to allow the tissues to be hydrated without increasing plasma volume,” Constantino Palestra told Divers Alert Network when asked about proper hydration.

Hydration is not the ‘be all end all’ of efforts to avoid decompression sickness, it is a far less important risk factor than the dive profile, but it is one of the many things divers should take care about.

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