With extended deco times that are becoming more common with the deeper offshore dives, the potential for an incident involving the rescue services has increased. The risk can be reduced to an acceptable level if certain guidelines are adhered to.

Given ideal conditions, loads of slack water time, calm & sunny, good vis above and below the water, then the chance of a problem diminishes: but occasionally we leave the marina late because someone got caught in traffic, the sea state is a 4/5 instead of a 3/4 thus increasing our journey time, we are on a spring tide, surface vis is only a mile or two, etc.

It would make more sense to go for something closer, and we sometimes do, but more than likely everyone is psyched-up to dive the planned wreck and are eager to press on.

So we get on site, the shot is rapidly deployed and kitting-up is in progress. A bouncy journey has delayed this a bit, while one or two are sea-sick. So eventually we get everybody in, though the last pair may have encountered a bit of tide going down the line. The worst scenario is when it may have taken up to 40 minutes to get everybody in.

In view of the expected tide on ascent, everyone has agreed to use surface deco marker buoys.

The die is cast for an incident.

If deco times are protracted, and bottom times vary considerably, then it is inevitable that divers will be spread out over the ocean, particularly if someone insists on hanging on the shotline, while others drift.
This immediately puts the skipper in an impossible position, trying to cover all divers.

With the help of my track plotter I can keep track of where divers are and their drift rate and direction.

But if anyone has a problem and  requires immediate recovery, tough, I may not be there, but 5 minutes away.

So what is the best solution?

Deco Stations

By far the safest system is a deco station clipped to the shot line via a 30m lanyard. The station should be simple and easily deployable. A skipper's nightmare consists of chains, weights, 3-level scaffold tubes and buoys all over the place. Forget it. Use one aluminium tube(may be 2 joined) suspended at  each end from a 5 gallon drum at say, 6m. A slate should be tied at the clipped end of the lanyard so that each diver can check himself off or tear off a tape. The last one up the shotline unclips. As there may be some tide and strain on the line, a large snap shackle is required. Some degree of planning is called for. Each diver must obviously get back to the shot. The first pair of divers down need to tie this in to prevent it moving, with a piece of sacrificial cord so the skipper can break it out later. If the vis is poor or the wreck unfamiliar, divers will have to reel-off. It is a temptation not to use a reel/line, but it is all too easy to become disorientated, run low on gas and have to make a free ascent. People have even come up a rogue shotline, lost by a previous diveboat, which will obviously  not have the station on it. It may not even reach the surface, the buoy gone or submerged. Problems may still occur, so the team must agree a time to disconnect the lanyard if the full compliment of divers do not arrive on the station.

An even simpler solution is the Lazy Shot, which has the advantage of transportability and ease of deployment without prior planning, if, for instance, conditions on site deteriorate. This consists of the 20m lanyard clipped to the shotline by a breakaway clip. The other end  is fastened at minimum deco depth to a buoyed line. Trailing from this is a 30m tail having rings lashed at 3m intervals. Divers come up the lanyard and move to the furthest position where they deploy their SMB. The  best type of line is soft 10mm   polyester or nylon that can be stowed in a cut-down 5 gallon drum and deployed from such. Brightly coloured buoys are best.

Each diver is safer on the station in that if someone has a problem, plenty of help is at hand. The skipper can provide most effective surface cover and divers occupy the smallest area of sea if other traffic appears. The skipper will hopefully be able to recover his shotline before the tide makes it difficult, and may even be able to turn off engines and drift along with the station!

SMB'S

These have become widely accepted  as one of the best methods of decompressing, from the divers viewpoint. It means not having to reel-off on the wreck, thus doubling the exploration range. Their use require skill, practice, and a good reel carefully filled (not too full) with knotless line. Jams occur, and without a buddy's back-up SMB you are without a vital piece of safety kit. Its always worth having a spare.

They are best used in fair surface conditions, moderate sea state, good visibility and the less tide, the better. Hence the need to be ready to dive at the predicted slack water time, and to get everybody into the water promptly, within 20 minutes. With the plethora of gear some techies are carrying, this may not be easy, but with maybe only 30 minutes of slack you have got to get your act together.

The visibility of SMB's varies considerably. In a F5 it may be 500m, assuming an erect, orange 1m tall buoy is used in fair daylight. Even then the buoy is probably visible for only 1 in 4 sec.
Unfortunately some people insist on using the skinny yellow floppy sausage buoys, etc, which reduce the visibility by half or more.
Buddy bags with their own air bottle are  excellent.
Make sure there is sufficient weight on the bottom of the buoy to keep it erect.

So get wise and follow these rules if you do not already.

1. Carry an adequate self inflating deco buoy plus reel which will not jam up. If you dive alone it pays to double-up; you do not have the redundancy provided by a buddy. A lifting bag does not make a very good substitute for a deco bag, but it is far better than nothing. If you dive as a pair, deploy both deco bags to improve visibility to any surface vessels, and to let your skipper know there are 2 divers below. He can then account for all his flock. Paint your name in large letters on the buoy. Flags are effective on the surface if they are large, Day-Glo orange and held high. Lanterns switched on and held high towards the boat are effective, particularly on an overcast day.
2. Carry an EPIRB. It's a small price to pay for the reassurance that if the cover boat has a big problem like a fire, engine breakdown (may not have twin screws) or loses sight of you then the SAR services can be alerted.
3. Flares are of limited use, assuming  they survive the dive. They last for such a brief time that unless one is looking in the right direction at the right time, they may not be seen.
4. Get to the Marina in good time to set up your kit and check it out. So many times a trip is jeopardised by a latecomer.

SAR

Paul's Helio Trip

Back in December 21st 1997 we did a Moldavia trip where the unexpected occurred, fortunately with a safe outcome.

It was a calm, overcast day, NW3 on a neap tide. The underwater vis was apparently up to 10m. As conditions were good, the use of SMB's for deco was agreed. I would pull the shot when all were on bags, clear of the wreck. Some were diving as pairs and would deploy only one bag.

Everything went to plan; bags surfaced, I recovered the shotline and drifted along with the fairly tightly bunched group, until the last pair with a run time of 80 minutes were due to surface. We are now a couple of miles from the wreck in a 2 knot tide.

Only one diver surfaces. He left his buddy, Paul, early on in the dive.

So we have a diver missing, it's early afternoon in late December. I start searching uptide, knowing that if Paul is adrift without an SMB he cannot be that far from us, at least inside a mile radius. It is imperative to find him before dark. I quickly come to the conclusion that I need help rapidly, i.e. a helicopter.

I called Solent Coastguard and Rescue India Juliet was on scene in 20 minutes. Within 15 minutes they had located Paul way uptide from us. He was OK. He and his kit were lifted and returned to Spartacus none the worse for the experience. But what went wrong?

Paul was enjoying his dive when he came across a grapnel and chain which he sent up on his lift bag
( probably thinking of the skipper). When his allotted bottom time came up he deployed his SMB from the wreck, but the reel jammed, so he cut the line, freeing the buoy. I probably recovered it, a fairly regular occurrence, and thought someone would be relying on his buddy for an SMB.

However, cool-headed Paul tied one end of his reel line to the wreck and gently unwound it to control his ascent. At deco depth he did most of his stops, still tethered to the wreck. I would imagine this becoming increasingly difficult as the tide increased, Paul inflating his suit/ jacket more and the tension on the line increasing making it very difficult to maintain 6m. Not to be recommended.

The result was, of course, that when he did surface, he was some considerable distance from the boat and other divers.

I now make a point of always returning to the wreck, however far it is away, before searching downtide. This may take 10 or 15 minutes, though, and if you have a rebreather, I will not see your exhalation bubbles on my echo-sounder.

Sadly, Paul  died on the wreck of the Afric the following year, doing what he loved, deep diving.

"Plan the dive and dive the plan" and hopefully you will never require the rescue services. But "to err is to be human", kit fails, divers get narced, or just lose track of time in crystal-clear vis or strap themselves up with goody bags instead of using lift bags.

The result is often missed deco and an expensive helicopter ride to Haslar, the nearest recompression facility.

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