MOST OF US ARE INTERESTED IN THE DETAILS of diving incidents we read about in DIVER News - not just for curiosity, but from a sense of self-preservation.
Our scenarios are based on incidents that really happened, either in part or compounded together. To put them in perspective, we assembled a panel of divers covering the whole spectrum of experience and qualifications, from up-and-coming newcomers to a technical instructor-trainer (see panel).
Your weightbelt falls off into a narrow hole and can't be retrieved. You grab the nearest bit of wreck or reef. The situation is stable, but you can't stay there forever...
Let's start with the relative beginner: "My first priority would be to dump as much air from my BC and drysuit as possible. I would then get my buddy to fill my pockets with rocks or other heavy objects," said Calum Roke.
"Failing that, I would tie off the line from my reel and use that to slowly lift myself to the surface."
The other divers all came up with much the same solution, the more experienced emphasising the finding of their own solutions, rather than getting their buddy to help.
On the subject of help: "I would also get my buddy to dump all their buoyancy and hang on to me to provide additional downforce," said Lynn Campbell.
Another option came from Kate Jopling. "Before winding myself up on a reel, I would look for the shotline and use that to control my ascent," said Kate. It may seem obvious, but she was the one to spell it out.
I have witnessed a similar incident in which the diver winding himself back to the surface lost control of his reel during a gas switch.
A combination of immediate oxygen, precautionary treatment in the chamber and luck meant that he showed no symptoms of decompression illness, and was back diving a few weeks later.
This doesn't invalidate the use of a reel, but does highlight the need to ensure that the line is secured at both ends, and not to rely on the ratchet or brake to hold against such stress.
Your mask breaks or falls off and gets lost. If you carry a spare, it has broken in your pocket. In the course of all this, you lose your buddy. You're alone with no mask...
"First I would wait for a minute while my buddy looks for me," said Lynn, staying focused on the value of a good buddy.
Without a buddy to help, there is no option but a blind ascent. "I imagine it would be very easy to panic and go rocketing up. Hopefully you can still see your gauges, or be able to safely judge an ascent rate," said Calum.
So what techniques are available for that?
"You should be able to deploy your DSMB blind, then reel slowly up," said Sally Sharrock.
"Use the rate of reeling as a guide to speed," said Oli Brown.
Andy Hayhurst had measured this: "I would count three or four turns per metre."
"Depending on how broken my mask was, I would try to hold it on so that I could read my computer," said Kate.
Some dive computers give audible warnings. "It would bleep at me if I were ascending too fast or if I was missing a stop," said Lynn.
On suggestions for gauging depth: "It would be a guess, but I would feel the amount of line on the spool," suggested Oli.
Andy was more precise. "I have knots on my line at 9m, 6m and 3m, with corresponding numbers of knots for depth, just for this scenario."
"If all else fails, stop when the water gets lighter near the surface," said Sally.
How would they time decompression stops?
"I would count seconds and do the stops over
a range of depths for as long as possible," suggested Oli.
"While counting I would add 50% for mistakes," said Andy, "then be prepared for a weight-ditch and swim up if I ran out of gas."
I have knots on my own line, and also find them useful during normal ascents, but would caution that on some types of reel they could lead to jamming.
On a deco dive in the UK you look round to see your dive buddy still, and apparently not breathing...
This scenario is one that most of us train for to some extent, but there is an element of personal assessment of how much risk a rescuer is prepared to take. Our divers' responses also reflected the type of diving they are used to, from no-stop to extensive decompression.
They all began by giving a gentle shake and tapping on the buddy's mask to see if there was
a response. "If they are on CCR I would also do a diluent flush and check the handsets," said Andy.
With the buddy not responding, our divers agreed that the only option was to get them to the surface. Sally summed it up nicely: "He's not going to recover down there."
"I would not do any stops," said Kate. "I would have oxygen once in the boat and would contact the diver medics for further advice."
"The buddy is the priority, so take him to the surface. DCI can be treated and shouldn't be life-threatening," said Calum.
"If I had minimal decompression left, I would surface with him," put in Andy.
We are now getting to the dividing line between ascending with the casualty and sending him up alone. "Don't ascend at a rate that will harm you, or there will be two casualties, not just one," said Lynn.
"Send him to the surface and follow up yourself as fast as is safe," said Sally.
"Me getting bent will just complicate an already bad situation, so I'd drop his weightbelt and send him up. To get attention, I'd attach a second DSMB to my line," was Oli's solution.
Andy would do similarly. "I would send up both our yellow DSMBs as an emergency signal to prepare the skipper. Once I knew the boat was overhead, I would inflate his BC and send him up the line clipped-on. One dead is better than two!"
I asked the divers for scenario ideas, and several proposed variations of our next incident. You are on a wreck in low visibility. You decide it is time to come up and start ascending the wreckage. You bump your head. In the low visibility, you have managed to get inside the wreck...
"I would try to stay calm to control air consumption and then, keeping within touching distance of my buddy, would try to retrace my route into the wreck," said Kate.
"You should know which direction you came from," said Calum.
"Assuming I wasn't using a bottom line to reel back, I would find a reference point to turn 180°," said Lynn.
"...unless you can see a lighter direction, in which case head that way," was Sally's qualification.
"I would find a primary and secondary tie-off and use the direction of the line between them as a guide to vary my search direction," said Oli.
"If a sweep search doesn't work, follow a wall and use the reel to retrace and follow another wall until an exit is found," said Andy. "You could just sit still and see if the visibility clears, but searching on a reel is a better option."
"Once out, cut the line and tie it off to reduce the entanglement hazard to other divers," added conscientious Andy.
On a dive in the English Channel in calm surface conditions, you surface to see nothing but fog...
Our divers all agree on the advisability of using sound to attract attention. As Calum said: "Noise should travel well."
"Of course, you carry a whistle," said Sally.
"This actually happened to me. I wasn't too far from shore and the boat found us safely, but I've never dived without a compass since!"
"I would listen carefully for boat engines. In addition to blowing my whistle, I would also shout and wave my torch back and forth," said Oli, introducing visual signalling to the situation.
Kate added: "I would turn on my strobe and stick with my buddy. If we surfaced up a shotline, I would keep hold of it so as not to drift away from where the boat is expecting us".
"I would put up my DSMB with radar reflective material on it," said equipped-for-anything Andy, noting that these are made by Custom Divers.
"I would pull my hood down to aid listening, but keep my mask on and regulator handy, just in case I heard a big ship approaching and had to descend quickly. After 30 to 45 minutes I would switch on my EPIRB."
You book an offshore UK wreck dive as a buddy pair, not knowing any of the other divers on board. You surface to see your dive boat heading home and continuing over the horizon. You have been left behind...
As with the other incidents, our divers all included a few basic principles in their solutions, again summed up by Calum as "make yourself buoyant and as visible as possible."
All continued to stress the need to stay together. "Hitch yourselves together and get out that flag," said Sally, preparing for the worst case and a long wait.
"I would also switch on my strobe," said Kate.
The usual methods of achieving buoyancy by inflating BCs and ditching weightbelts were noted, but don't throw that lead away too soon. "I would put a bit of weight on the bottom of my DSMB to make sure it stays standing up the whole time," said Oli.
"Put up as many signal devices as possible," advised Andy. "Between us, my buddy and I should have six DSMBs and four flags. I would give it 30 minutes before I switch on an EPIRB, then deploy a surface dye if I hear an aircraft."
Would they swim for it? "Wait." said Lynn. "They should notice when they get back, if not before."
"Don't swim - someone on the shore or at home should realise you are missing," said Calum.
"It would depend on how far offshore I was," said Kate.
Would the situation change if they were overseas in warm water?
"Same as before really, unless you know in which direction the shore is," replied Sally, more prepared to swim for it when abroad.
"There would probably only be two DSMBs and no flags," said Andy, but added: "I carry a signal mirror when abroad. Flashing that can be effective. Many holiday sites are close to shore, so a slow swim while keeping DSMBs aloft would be worthwhile."
"We would need to stay protected from the sun," said Calum. Having seen the film Open Water, he noted: "Pray that they miss the rental gear."
"At least it would be warm," concluded Oli.
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