Near Drowning Incident: 5th August 2009 Options

[Rob Dobson]

Location: Lerwick
Weather: Warm for Shetland (15C?)
Wind: 5-6
SeaState: Moderate Swell (2m?)
Rebreather: mCCR Megalodon (Mods: Long Can, 5.5lb Radial Scrubber, Manta BMCL's, Off board o2)


A week ago I was discharged from Lerwick Hospital following an incident at depth whilst diving the wreck of the Glenisla around Bressay Sound (Shetland).

Days before the trip to Shetland I swapped out the CLs on my CCR moving from OTS to BMCL in order to free up the chest area and make it easier to carry multiple bailout bottles. It wasn't bad planning that lead me to making the change so late on but that was the earliest I was able get hold of the parts required. It left me no time to test the unit before my arrival in Shetland so we arranged a check out dive in 4m of water to make sure that everything was OK ahead of the first dive. The unit passed all of the pre-dive checks including head pos & neg, stereo check, loop pos & neg. On the check out dive I noticed that the WOB whilst inverted was appalling and that the breathe generally was quite wet. I checked over everything again on the surface and repeated the pre-dive tests which again it passed.

The first actual dive was to <40m. It was a great dive, the BMCL's trimmed well but again the breathe was very wet. I put some of this down to the fact now any fluid in the loop is going to drop down into the mouthpiece as the CL's are effectively higher than my mouth. That was just something I was just going to have to get used to; I couldn't account for the amount of fluid or for the fact that some of it was clearly seawater. Again I stripped the unit, checked it over and repeated the tests - again everything checked out.

I then lost two days diving, one to recover from an accidental mojito overdose and then the weather closed in for 24hrs.

The next dive was the Glenisla (42m), my last chance to get happy in the rig before we moved onto the more demanding wrecks in the 65m-95m range. As it was a relatively shallow dive and we were getting low on He I opted for an air top on my left over 10/50 Dil which gave me a mix of 16/27. I was using 90% as an off board rich mix in case I lost my o2 and I had 220 bar of 20/25 in a 7L as bailout (1540L). I was diving an online Shearwater set to 10/90 on ZHL-16 GF and an X1 as a constant PPo2 backup set to 1.25 running V-planner Live VPM-B +3. I run the unit at around a 1.3.

Before I jumped in I was discussing the location of the bailout reg with my buddy (a CCR instructor). He made the recommendation of having the bailout reg bungeed around the neck in the same way that you have a backup reg around your neck when on OC. This is something which I had been considering for a while and seemed like a good opportunity to try it out ahead of the more technically demanding dives coming up later in the week. As I typically scooter all my stages / bailout are usually carried on my left, but as my regs are Apeks Tx50's they are fed from the right I had to move my bailout from my left to my right to accommodate the gas feed.

Going down the shot line I could hear gurgling going on in the loop, the sort of gurgling that I would expect to hear after about an hour in the water. When I got on the wreck my suit was running too tight and for some reason my suit inflation wasn't working. I shut the valve off on the suit inflation bottle and reopened it. For some reason this cleared it and I was able to get gas into my suit to relieve the squeeze. I signalled my buddy that I was OK and we went off to assist in the recovery of the shot weight.

As I hung back illuminating the work being done to attach the lift bag I got a mouth full of sea water out of the breathing loop which I simply swallowed. When the lift bag had been sent to the surface we set off to explore the wreck and I was again getting a significant build up of seawater in the breathing loop. I went head down and rolled to the left to direct the water over the OPV in the exhale CL and added DIL to blow the water out of the lung via the OPV. I returned to a trimmed position and got another mouth full of seawater. The manoeuvre had not worked so I closed the loop, spat the water out and exhaled into the mouth piece as I re-opened the loop. There was still a lot of water gurgling in the loop so I repeated the roll and expel manoeuvre and again it didn't work so again I took the water into my mouth and spat it out into sea having closed the breathing loop.

Barry tried to get into a section of the wreck but didn't fit "You try, I'm too fat!" so I went around a small circuit and came back to him in which time the loop was almost flooded again. I pointed at my CL's and did a 'wanker' sign. "This is breathing like crap." I told him and as I inhaled I took water into my lungs causing me to cough uncontrollably. I inhaled hard as a reflex action and took more seawater into my lungs. Having got the coughing under control I sucked water into my mouth, closed the loop and spat the water out and exhaled into the loop as I re-opened it. Again I inhaled and again I got mostly water out of the loop. It was still feeling like no more than a minor inconvenience at this point. There were plenty of divers nearby carrying plenty of gas and I could see the OC divers to head for with their large cylinders and their contingency reserves.

At this point I was starting to get a bit flustered and went to bailout, I closed the loop and discarded it. I looked down to my left - no bailout. The muscle memory had taken over and it took me a moment to remember that I had moved it to under my chin. I reverted to OC mucsle memory and went under my chin for the reg - nope, it wasn't there either. Being connected to a side slung bottle on the right meant that the reg was pulled slightly over to the right and not where I had reached for it. I was still frantically trying to grip it when Barry thrust his bailout reg in my face. I grabbed it, stuck it in my mouth, purged it and inhaled deeply.

I got water again. At this point flustered became panic and I was actually surprised that I was still alive. I'd had four consecutive blasts of seawater and I can remember thinking two things simultaneously:

'Now you're fucked' and '40m feels a long way down when you've nothing to breathe'.

Coughing seawater through my nose I went to grab the bailout regulator from around my neck, but again my hand went to the central (OC) position and not to right where the reg was hanging. Out of sheer desperation I grabbed the breathing loop which I knew to be useless and shoved it my mouth and opened it. I sucked from it for all I was worth fully expecting to get nothing but a final and fatal dose of water; but what I got was sweet, sweet breathable gas. I was coughing, I had water coming out of my mouth, my eyes and my nose but I was alive and calming down. I took a few long breaths and signalled to Barry that I was OK. When I had gathered myself together I told him 'I'm OK.... that was close... OK.... I'm getting out of here. This thing is fucked, I need to get up.'
'Need me to come with you?'
'No, mate - I'll be fine. You go and enjoy your dive but I need to get out of the water.'

With that I started my ascent back up the shotline. I'd gone 3 or 4 meters when I got another mouth full of seawater of off the breathing loop. I was half expecting this because nothing had actually been fixed and so I causally bailed out on to my OC reg and carried on the ascent. My first scheduled stop was a minute at 21m. I got to 21m and and checked my Shearwater for my next stop and my current stop incremented by a minute. This threw me but I also became aware of how hard I was finding it to breathe. Was I getting low on gas? Was I over breathing the reg? I was breathing hard, way over my usual OC SAC rate but it wasn't panicked out of control breathing. I started doing a quick gas calculation as I searched for the contents gauge before I had a sudden reality check: who gives a fuck how much gas you have? Just get your ass up!

I made a conscious decision to blow my stops off until 6m working on the assumption that I can run out of gas completely and still make the last 6m. It was a traumatic but controlled ascent to 6m. I was breathing heavily but I wasn't out of control and yet it still felt like I was drowning. My thirst for gas was never sated and it felt like I was constantly on the verge of suffocating. I got to 6m and took stock of the situation... I checked how much deco was showing on my Shearwater; if I recall correctly it was 25 minutes, but it may have been 15... Whatever it was I decided that it was more than I could do... I couldn't breathe and therefore I was better off suffering from DCS on the surface than drowning clearing my stops. I went for the surface.

At the top of the shotline I could see nothing but walls of water and hear nothing but this horrendous wheezing sound; it was a sound somewhere between a Rottweiler barking through asthma and someone who has been stabbed in the lungs whilst running a marathon. As I was desperately snatching glimpses over the swell looking for the MV Valkyrie it dawned on me that the sickening sound was the sound of my own breathing. I had all the air in the world and yet I still couldn't breathe.

I caught sight of the Valkyrie, she was heading away from me maybe a quarter of a mile away. I waved at the Valkyrie for all I was worth before I dropped back into the trough between waves and she was out of sight again. I thought that I was going to drown on the surface. I wasn't expected, I was early, I hadn't sent up a dSMB so no one knew I was coming up. I kept waving, coughing, wheezing for breath, waving, coughing, wheezing, waving... Saltwater kept spluttering out of my nose and mouth. Still I couldn't breathe.

When I next caught sight of the Valkyrie she was mid way through a sharp turn. Then she was heading directly for me at speed and moments later she was alongside me. The relief I felt was overwhelming. I wanted to give her big green hull a massive hug and a big wet girlie kiss. I was however still struggling to breathe, struggling against the swell, still not onboard her and strangely rooted to the shotline.

The MV Valkyrie. Never have I been so relieved to see a large boat bearing down on me at speed:



Helen was on deck and yelling at me. I couldn't understand what it was she was shouting but I saw the yellow life line in her hand. The next thing I realised she had thrown it to within about a half an arms reach of my location; a perfect throw, first time and under pressure. I grabbed it and Helen started pulling me in towards the boat assisted by Mary who had sat the dive out. I only got part of the way and I could feel myself being pulled back towards the shot. On some level I knew I was tangled but I refused to accept it. I was too close to safety and I was focused on getting out of the water. Again they were pulling me towards the boat and again the shotline was pulling me back towards the abyss. Then Hazel was there, down from the wheelhouse and yelling at me. I still didn't hear what was being said but I knew I had to deal with the shotline. Turning away from the sanctuary of the boat to look for the line that was snaring me was a hard thing to do, it felt as though the light at the end of the tunnel had suddenly become dishearteningly dim.

As it turned out disentangling myself was very easy and within seconds I was on the lift and after some minor repositioning I was up to deck level and being rapidly stripped of all my kit. I was sat down and Hazel looked me in the eye and spoke very clearly: "Rob, I just need to know one thing - answer me yes or no: have you been cocktailed?*" (i.e have you suffered a 'caustic cocktail' - inhalation of caustic fluid caused by water mixing with the sofnolime Co2 absorbing granules).

The question was unexpected. "No, just seawater."
"Thank you, that's all I needed to know." And with that she was gone.

I was still wheezing and struggling for breath. As I was helped out my suit Helen wanted more information: "Rapid ascent? How many stops have you missed?"
"Not rapid but I missed 15 - 25 minutes."
She talked into her radio "Hazel, you need to call it in." Well that's me going to the chamber... Where are we? Oh Shetland, that's right. OK, so the nearest chamber is where... Aberdeen maybe...? Oh fuck. ABERDEEN! That's only a 14.5hr ferry journey to get back and pick your car up... Fuck it. You're alive....

"OK Rob, I want you to lie down in the saloon. We're going to put you on o2 and wait for the lifeboat. Here's some rehydration salts, it tastes like crap but you have to drink it"
"Yeah, it's OK - I know the routine." I know the routine alright, I've seen it plenty of times before; I've just never been on the receiving end of it...

Helen asked questions and made notes whilst Mary went into my cabin to put together the standard goody bag for divers that are about to have their diving cut short in spectacular style:

Change of clothes (so you don't walk the streets of whatever city you get released into looking like you've over done it at a kinky thermals party)
Wallet (so you can get home)
Mobile phone (so you can call loved ones and tell them that the reports of your demise are somewhat exaggerated)
Book (something to read during the long hours you're in the decompression chamber)
Dive Computer (so you can accurately relay the dive profile to the hyperbaric doctors)

Before Mary was back with my bag the boys from the RNLI were alongside and I was being bundled onto a lifeboat. Once aboard I was put back on o2 and wrapped up warm as they opened the taps and zoomed off at mach 3. Holy crap those lifeboats can shift! In about 2 minutes we were alongside the harbour wall and I was bundled ashore and into the hands of the waiting ambulance crew. Back on o2, more questions and the tapping of details into a computer as we made our way to the hospital.

Lifeboats. So fast they make even the Cuda look slow:



The Lerwick casualty department is clearly not used to receiving divers. It took 30 minutes to get on o2 (I had to ask), I had to ask to be kept flat (to reduce the risk of bubbles forming in the highest point, the brain), I was not put on a drip, I had to suggest that they look for skin bends and every decision had to be relayed via courier pigeon to the hyperbaric doctors in Aberdeen. Lots of curious interns kept turning looking sheepishly and saying "Hello, I just wanted to see you. I've never seen a diver before. Do you mind?" I was sent for an X-ray of the lungs and rigged up to a heart monitor before being kept in overnight for observation.

I knew I wasn't symptomatic fairly quickly but my lungs felt like they were burning with every breath and to my mind secondary drowning or permanent lung damage was the thing that I was at risk from. My X1 recorded that my maximum TTS was 13 minutes so realistically according to VPM-B I only missed around 11 minutes of stops; not that big a deal. The hospital were fixated on DCS and seemed unconcerned by anything else. After about 5 hours I was making strong noises in the direction of being discharged but they were having none of it. Clearly I had forgotten that the alternative was whisked away to Aberdeen... After the visiting Hazel, Helen and Barry left I settled down to the comforting soundtrack of 'Mr Hacking Cough of the Millennium' and 'Mr Random Groaning - World Champion'. At 3am I was still wide awake so I asked for 'either a set of ear plugs or a carving knife'. They moved me to a quite room.

This what fucking up a dive feels like:


The next morning I was seen by a doctor who reviewed my X-rays and conducted a neurology exam before discharging me. My lungs felt much better but I took a day off to be sure, during which time I swapped my CLs back to the OTS ones ready for a 60m dive on the Friday which was very pleasant passed without incident.

Analysis
After the event Barry and I striped the unit down. The OPV took four complete turns to tighten it into place on the exhale CL. I had suspected that the OPV was the cause of the water ingress but I still cannot satisfactorily explain how the unit repeatedly passed the pre-dive positive and negative checks. The issue was not the mouth piece or the hose as by swapping the CLs back the problem was rectified.

With the water getting into the exhale lung it is not clear how I came to inhale it. I believe that exhaling opened the flapper valve with the water already up against it. This allowed the water to pass into the mouth piece where it combined with the inhale gas and was sucked into my lungs. Only speculation at the moment but I will be engaging with the manufacturer in an attempt to identify the actual sequence of events.

If something isn't right going down the shotline then it's not going to magically better at depth - just call the friggin dive.

I actually don't have gills afterall. 42m is a long way down when you have nothing to breathe. I had become complacent in this depth range and thought that it was acceptable to troubleshoot clearly faulty units in 'only 40 odd meters of water.' This is contempt towards a dangerous environment. It is arrogance and it bit me on the ass, very, very hard.

Human lungs get sticky very quickly once they inhale water. This makes breathing very difficult regardless of where you are. Sounds obvious but this is not something I had ever stopped to consider before. So if someone has inhaled water they are in trouble even if this is not apparent at the time. Get them up and stay with them.

The RNLI are brilliant. From now on I am giving them money every month via direct debit. I felt such a selfish prick explaining to these volunteers (who have just dropped their day jobs to go out on a shout), that the reason I am there is because I chose to jump off of a perfectly good boat to go and look at one that sank over 90 years ago. Diving is very hard to justify to those who you inconvenience in the process.

The reason my X1 was saying that I missed no more than 11 minutes of stops and the Shearwater was telling me it was 25 minutes is for two reasons: firstly ZHL-16 penalises the use of He more than VPM-B and more importantly I never told either computer I had come off of the loop. As the PPo2 dropped in my loop the Shearwater thought I was still breathing that which is why the stops incrementing even as I was doing them. The X1 thought I was sticking to a steady 1.25.

Helen and Hazel on the MV Valkyrie quite literally saved my life. Hazel must have Spidey senses for noticing that I was back on the surface so quickly, in such high swell and without being due. Helen's throw with the lifeline was perfection under pressure. Getting alongside me and getting me onboard so quickly in difficult conditions was the difference between me being here and not. Model professionalism from start to finish. Thank you, thank you, thank you.

[neilh]

A sobering report Rob - thanks for sharing. Great to see you coming out on the right side of an incident.

There's often reports of the superb service the RNLI provide - which is one reason I also support them as and when I can. Happily there are fewer reports about Helen and Hazel - but everything I've heard and experienced proves to me they are just the people you would want around at a time like that. Well done for looking out for Rob girls.

[GLOC]

Fucking hell Rob.

Well done on coming back. Even more dues to Helen and Hazel for saving your sorry ass!!

Take care

[Simon TW]

Thanks for writing this up Rob.

I'm glad that you're safe and well.

[Chris at Silent ...]

Thanks for sharing. I like the holiday snaps too. "heres one of me at the hotel, heres one of me kitting up for diving, heres one of the Lifeboat, heres one of the chamber..." You cant get that at Disney!

I have a BOV with offboard OC bailout connected and on at all times for these kind of reasons. Used it yesterday actually, when I was also doing a 40m dive in a strong current. I felt like I was overbreathing the counterlungs and couldnt get as much gas as id like, so I just twisted the knob, took some nice long slugs of OC and that got my breathing back under control.

Obvioulsy wouldnt work in a near drowning event, but bail out to oc on the decent and then calling the dive would have had a better outcome.

Well done all the Emergency Services too! Over here, you would have been getting bills in the mail for around $50k by now.

[Rob Dobson]

I have a BOV with offboard OC bailout connected and on at all times for these kind of reasons. Used it yesterday actually, when I was also doing a 40m dive in a strong current. I felt like I was overbreathing the counterlungs and couldnt get as much gas as id like, so I just twisted the knob, took some nice long slugs of OC and that got my breathing back under control.

Obvioulsy wouldnt work in a near drowning event, but bail out to oc on the decent and then calling the dive would have had a better outcome.

Chris - I used to have a GG BOV on my unit but it played havoc with the WOB and so I took it off and waited for the ISC version to be released. If I had a BOV then yes it would have made the bailout less of a circus and I would have avoided at least one slug of saltwater into the lungs.

The reason I didn't call the dive going down the shot was because I wanted to identify where the water was getting into the loop. Basically I was focused on the dives coming up and not focusing on the dive I was on. There must be a friggin Darwin Award with my name on it somewhere...

[MartinH]

There was a similar incident reported over on RBW from a guy who switched to the Manta CL's and had flooded loop as a result of a loose OPV. Again the unit had passed the pos and neg pre-dive. Scary shit.

Why only 24hrs out of the water and was it wise to get back in and do a 60m dive the day after?