Thailand – Australia – United Kingdom

When Divers Go Missing

HAVE YOU EVER SURFACED AFTER A DIVE to find yourself alone, with no boat in sight? It’s always a salutary experience, even if it doesn’t end in disaster. At DIVER, we were made aware of nine such incidents involving 28 divers in the first half of 2008 alone. The reefs of Suakin, in southern Sudanese waters, are deep columns of coral that hardly breach the surface. There is nowhere to anchor, and little shelter from the north-west wind. Our boat captain’s solution was to send the deckhand down with a wire hawser to lasso a likely coral head on the reef wall, and attach a mooring line to it. It usually worked. I was a dive guide back then, and it was after a dive on such a reef that I surfaced with all my passengers to find that there was no pick-up boat, nor any sign of our liveaboard.

It’s a strange feeling to realise that you’re just a speck in the ocean. Luckily we were next to the reef, and I was able to shepherd my flock into the lee of the current. Evidently the coral head had come loose from the reef wall, and the boat crew had found themselves with several tonnes of rock dangling from around 80m of mooring line. It was too much for the winch to lift, and the only solution had been for the deckhand to make a seriously deep dive with a hacksaw to cut the hawser. The undertaking took two attempts, with a long surface interval between them. Meanwhile, the diver pick-up boat was needed to keep the main vessel pointed away from the many reefs. We divers were temporarily abandoned. We had plenty to talk about but we didn’t know what had happened to the boat. The first couple of hours of feeling abandoned are the worst. Then a feeling of inevitability overcomes you. People become passive, even the normally animated Italians I was escorting. We stayed put, and the story had a happy ending. However, since then I have always carried a surface signalling device – a big fluorescent yellow flag on a long extending pole, attached to my tank by two elastic straps.

Our boat crew had known where we were, but this is not usually the case. Ocean currents are such that divers can drift huge distances and become very hard to see. Six Japanese divers were lost near Palau and their bodies were found too late, but not before one had written on her slate: “We can see you searching for us, but you can’t see us.” After an incident that involved a boatload of British divers going missing at the Brothers Islands in the Red Sea, the Egyptian authorities regulated that every diver in a marine park should carry a surface marker and a working lamp. The divers were found only once it had got dark and their lights could be identified.

Another group separated from their boat at Elphinstone were less lucky. Only one survived, after he made the long swim to the shore. This May, two divers on the Great Barrier Reef were rescued after a long spell at sea. Soon after, another group of five (including three Brits) made the news when they were “swept away on a strong current” at Komodo Island in Indonesia. Strong currents often mark the best dive sites. I have used my flag in earnest in the Mergui Islands, Maldives, Galapagos; after the quick drift-dives of Aldabra; and after almost every high-voltage dive at Cocos and Malpelo. Anywhere with current and seas less than flat-calm can cause problems for boat crews trying to identify an unmarked diver at the surface.

SMBs
We tend to rely on late-deployment surface marker buoys in the UK, but these are effective only when they are deployed when and where surface watchers expect them. The standard sausage-shaped buoy is quite hard to spot when it is a tiny vertical line a long way off. A huge mother buoy like this one from Aquatec is something else. It needs its own air supply, carried in a 200ml or 400ml auxiliary cylinder.

Radar patches
Some divers put great faith in radar-reflecting patches attached to their suits. However, in anything but a calm sea, it’s only the patch on your hood that will be visible to a radar-equipped search vessel.

Flags
The biggest problem seems to be getting your signal marker high above cresting waves, which is why I am a great fan of the flag. It can be raised on its extending pole above the swell, and forms a horizontal shape with an attention-grabbing flutter on a sea breeze. It’s cheap to buy, lo-tech and I always know it will work. But this is not the only solution to attracting a rescuer’s attention.

Lights
At night a lamp can mark your position, but not if you have just used it for a night dive and the batteries are about to be exhausted. It’s worth keeping a separate lamp for emergency use in a BC pocket, perhaps one of the new ones (below) equipped with a high-output LED that gives a generous amount of burntime for a set of batteries. An emergency strobe beacon of the type that is rated to as much depth as you are ever likely to take it will give a piercing flash of light in all directions regularly and for many hours. The Jotron AQ-4 (left) is depth-rated to 200m, and will flash 50 times a minute for up to 12 hours.

Noise-makers Very loud whistles of the Buddy Blast type (left) can be attached to the direct-feed inflator of your BC (or put on a stand-alone hose) and use compressed air from your tank. Their ear-piercing screech can attract the attention of your pick-up boat driver if he is inattentive when you surface.
He will probably expect you to surface in a certain area, and so know in which direction to look.
Even a plastic whistle tied inside your BC pocket is worth having ? after all, it weighs nothing. But don?t expect anyone to hear any type of whistle over the noise of a boat engine at full throttle, and if a boat crew does hear an unexpected whistle, They still have to work out where it comes from, so visual indicators are important.

Flares
Flares come in numerous shapes and sizes. Some produce a coloured smoke that will make a diver into a larger subject for a searching aircrew, while an emergency plastic streamer does much the same but for longer (right). A parachute flare will give a boat crew an idea of the general direction in which they should be looking for a lost diver. One of my companions during that long wait in the Sudan sent up such a flare. It was very pretty and kept us all amused for a moment but I did point out that there was no point in sending up such a spectacular signal if there was no one there to see it. Questions were also asked later about how he had managed to transport a set of flares from Italy to Asmara airport, where we had collected him! All flares must be carried in a watertight container, and you can’t be sure they will work when you need them.If you have any, don’t use them unless you know that someone relevant can see the light. It’s the crucial point with all attention-grabbing surface devices – someone has to know you need rescuing.

Radio beacons
EPIRBs (Emergency Position Indicating Radio Beacons) are fitted to all passenger-carrying aircraft, life-rafts and lifeboats. They automatically transmit an emergency signal that can be picked up by satellite, and worldwide emergency rescue services can be alerted. Personal Locator Beacons (PLBs) were originally mis-sold as EPIRBs until the UK Coastguard rightly pointed out that they were not sufficiently powerful, nor did they use the now-current 404Mhz frequency – so no message to Tracy Island, and no Thunderbirds launched. Neither are EPIRBs really suitable for the quick response needed by divers. It can take up to 90 minutes for rescue services to be alerted this way. However, using a different radio wavelength (121.5Mhz), these PLB devices can be very effective over surface distances of around three miles – provided the search vessel is equipped with a suitable tracking device, and more when the beacon is sought from the air. In the UK, lifeboats are so equipped. However, there is no point buying a lone transmitter for use elsewhere if no tracking device is available. And there remain the vagaries and possible unreliability of batteries and electronics under water. Some PLBs now use both frequencies, but need enclosing in a waterproof case for diving. A strong outgoing signal can be ensured by combining the unit’s flexible aerial with an inflated SMB (pictured). The Undersea Hunter group of boats operating at the remote Cocos Island in the Pacific equips every visiting diver with an emergency-only PLB transmitter, and the crews are well trained in the use of the tracking device. Meanwhile a German company is promoting a new tracking system called ENOS (see separate test).

Reflectors
Some divers carry an old CD with them. It can be used to flash a reflection of the sun, if there is one.
But you can’t just flash at will with a signal mirror – you must create a visible and consistent reflection of light in the direction of your potential rescuer.
Years ago it was possible to buy a heliograph for divers. It was simple to aim it by means of a sighting device, so at least you knew it was doing its best to tell people you were there. It didn’t prove popular in the marketplace.

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One response

  1. Great info, Maldives is a perfect place for scuba divers. Rich in marine life and fabulous coral reefs!

    June 27, 2009 at 1:27 am