Emergencies – Page 15 – Learn to Dive Today Blog

Oral inflation

As I have mentioned before, problems arise when we don’t follow our training. I was working at a busy resort as skipper, Divemaster and Instructor. On a busy day I would kit up at 6.00am, launch the boat, dive, hit the beach to collect the next group, quickly change cylinders and head straight back out again to dive, sometimes doing four or five dives a day. We would only be done by early evening so there was no time for kit maintenance.

I had a problem with my inflator during the last dive of the day and quickly replaced it with a spare from my dusty tool kit late in the evening. Being too tired to fetch a cylinder I did not test it (mistake number one). The following morning I was distracted whilst kitting up and did not test it (mistake number two). The first dive of the day was to 40 metres. Being skipper and Divemaster meant I did not have too much time on the boat for a buddy check (mistake number three).

Half way down to the reef I intended slowing my descent and found my inflator was not working. Ah, no problem, I teach people how to orally inflate their BCD every time I have a student so I was not concerned. What I had forgotten was the pressure exerted at 40 metres on the bladder of your BCD is way more than you can imagine and oral inflation at that depth is a lot more difficult than it is at 18 metres. Instead of a few small breaths to reduce my descent it took a good eight or ten and by this time I was ready to bounce off the bottom.

The moral of my story: remember to always do a buddy check even if you have to do it on yourself. Don’t skip this step! And don’t change anything on your kit without testing it prior to dropping off a boat.

Out of air!

Out of air emergencies should not happen. Diving safely includes being sure that you have checked everything yourself, doing a buddy check and diving within your own personal limits. Always avoid making too many changes to your gear configuration and don’t test more than one new item at a time unless you are in shallow, confined water.

Most incidents are a culmination of several small mishaps and would most likely not have occurred had just one error being omitted. The other issue to be aware of is trusting your training and avoid thinking you know better. Here’s why…

I was diving in Mozambique, did a backward roll, and a negative entry (that’s when you don’t hang around on the surface with an inflated BCD, but start your descent immediately). Now, doing negative entries is not ideal, but the surface current was strong, we were diving a small reef and I wanted to get down quickly. So after the roll I finned down head first as fast as I could, without a buddy… Mistakes number one and two.

At 18 meters I found breathing to be difficult. Having just over-exerted myself I stopped to catch my breath but found as I reached the end of my breath my regulator stopped giving me air. Slow breaths were okay but it would not deliver what I needed. I instinctively looked at my pressure gauge, plenty of air in the cylinder but the needle dropped off as I took a deep breath.

“AHA my cylinder is not all the way open,” I thought so I reached up to try and check. It felt open, but convinced I was not doing it properly I took my kit off, held it in front of me and checked. The cylinder was all the way open, and now suddenly I was not getting air at all. I swam to the surface, slowing at about 8 metres to grab a few breaths from a buddy pair descending slowly.

On the surface I signaled the boat and whilst remaining in the water had the top man change my regulators – mistake number three. Straight back down to 18 metres I went, breathing normally and as soon as I turned face down to scan the sea for the group I ran out of air again. Back to the surface as fast as possible! A CESA from 18 metres is relatively difficult once you are stressed and short of breath from over exertion.

On the second descent logic was telling me the problem had to be my cylinder, but arguing with myself I dismissed this as I had serviced my cylinder less than three months prior to this and felt it could not possibly be at fault.

Back in camp I stripped my pillar valve and found it to be blocked with rust and sand. How could this be?

After investigating it turns out the cylinder was dropped from a vehicle a few weeks before this by the compressor operator. The pillar valve was damaged, so they drained it in a hurry, causing condensation, dropped it again in the sand, rinsed it with the water used for cooling cylinders whilst filling (salty water), emptied the water out, replaced the pillar valve with a used one, without a snorkel (a small pipe that runs from the bottom of the pillar valve into the cylinder). I got it back full of air unaware of the incident. The salty water inside rusted the cylinder, the absence of a snorkel meant that every time I was pointed head down the scales inside slowly drifted into the pillar valve until it was totally blocked.

It is not unusual for a little spot of rust to develop in a cylinder. It’s not ideal but it won’t kill you. However a snorkel ensures the pillar valve is supplied with clean air and the scales are kept out – in my situation in Mozambique, the scales would have settled around the top of the snorkel where it attaches to the pillar valve, instead of blocking the valve completely. The other end of the snorkel would have been a bit further into the cylinder, drawing clean air. When I took my cylinders to Orca Industries recently for their annual maintenance, I was very impressed that they insisted on checking each one for snorkels, and fitting them if they were absent.

Plan your dive and dive your plan

Three divers approached me at the dive centre one day, requesting I take them to a dive site where they could dive to 60 metres. They wanted to test some new equipment configurations. Two were certified advanced Nitrox divers, qualified deep technical divers and had made several dives to over a hundred metres… in a lake. The third diver, like myself, was qualified to dive to 40 metres.

So we draw up a plan: they will dive to 60 metres, spend 6 minutes at that depth, ascend to 50 metres and spend 5 minutes there, then ascend to 40 metres 5 minutes thereafter and so on until the reached 6 metres where they would switch to pure oxygen to reduce the deco stop time as the current at this site is strong. The third diver and myself would meet them at 40metres.

Using a software program called V Planner we calculated that including the descent time and ascent times for each stage, at a controlled rate, we would enter the water precisely 16 minutes after they started their dive and we would meet them at 40 metres. We would then all be together for the next 30 minutes, ascending with them to their 6 metre safety stop, ensure they had both switched to pure oxygen and then leave them and return to the boat.

The plan was that we would spend 6 minutes on our descent to 40 metres and all four of us would reach 40 metres together. They were made to clearly understand that should they have a problem at any depth deeper than 40 metres we would not be able to help them as we were diving 12 litre steel cylinders on a Nitrox 32% mix, limiting our depth – and what’s more we did not have the qualifications to go to 60 metres.

We discussed the plan in great detail and everyone was set. A red SMB would be hoisted if they experienced any difficulty and a yellow would be released once we met at 40 metres.

Mistakes happen

We started our descent on time, and watching my dive computer and timer I descended at the agreed rate. My buddy, however, did not. He descended way too fast. Believing that they would be in control of their dive he descended very fast and joined them, ahead of schedule at a depth of 55 metres. They were 3 minutes behind schedule as they had struggled to come to terms with the ocean current. Now we had a problem. I waited at 40 metres, but they arrived late, and this meant I would risk going into deco before we left for the 30 metre stop.

At this point my buddy ran out of air. He was closer to the deep divers as he was reading their slates, so he grabbed the first regulator he could see: the deco tank regulator, filled with pure oxygen. At depth oxygen is toxic and can kill you in a matter of minutes. I grabbed it out of his mouth, so he grabbed my regulator out of my mouth as he was now starting to panic. He was holding onto me so tight I could not reach my octo so I reached for the octo of another diver. So here we were three divers locked together at 40 metres, each with a regulator in our mouths that belonged to someone else. I managed to get him calmed and off my cylinder and onto the octo of the deep diver with the most air. Now back to normal, we started our ascent and did the required safety stops, reached the 6 metre stop for them to switch to oxygen and headed for the surface. I reached the surface with 10 bar in my tank.

My buddy had been to 55 m on a Nitrox mix of 32%. The maximum safe depth for this blend is 40 metres. He had almost sucked on a cylinder of oxygen at 40 metres, this is a lethal dose at depth. Mistakes happen. Be meticulous with dive planning, rehearse your incident scenarios and make sure you dive your plan.

FAQ: If I bleed in the water, will I attract sharks?

Hollywood has a lot to answer for!

For the girls

I get asked this question quite often by girls who are worried about diving while menstruating. The short answer, which should make you breathe a sigh of relief, is no – regardless of what feminine hygiene products you prefer to use. (While we’re on the subject – forgive me boys – but tampons are perfectly safe to use while scuba diving and nothing strange or frightening happens to them inside your body on a dive. If you’re really worried, and there’s no reason to be, use a Mooncup – get one at Wellness Warehouse.)

DAN has a useful answer to this question on their international website. The research that has been done indicates that menstruating women are at no greater risk of shark attacks than men, or women who aren’t on their period.

What you should be aware of is that if you’re a woman, you’re more susceptible to dehydration during your period, which in turn increases the risk of decompression sickness. There is also research that indicates that the use of oral contraceptives may marginally increase a woman’s risk of DCS. So be sure to stay hydrated, do your safety stops, dive conservatively – and enjoy your diving!

For the boys (and the girls who are still reading)

Sharks are not interested in human (mammal) blood – they prefer fish! And what’s more, unless you’ve experienced massive trauma (in which case I doubt scuba diving will be the first thing on your mind), only miniscule quantities of blood will be leaking out into the water – whether it’s because you’ve got a cut or scratch on your body, or (if you’re a girl) you’re menstruating.

(To clarify, in case you’re puzzled: I took these photos of the signs on the restroom doors at the Southern Sun Grayston hotel in Johannesburg with my dodgy cellphone camera while I was there for a conference in June. I’ve been itching to use them since, and frankly didn’t have time to organise a photo shoot of a woman in white trousers frolicking alone on a beach!)

Bookshelf: Diving science and physiology books

Sound boring? Doesn’t have to be. While your Divemaster instruction manual might make this stuff sound very dry, learning about what happens to the human body while breathing gas under pressure doesn’t have to be. Find some inspiration from this reading list when your theory gets too boring, or remind yourself of what you’re supposed to know already (if you’re a bit rusty).

For beginning divers: