- BCB International, 01222 464463
- Blandford Sub-Aqua, 01923 801572
- Advanced Diving Products, 01420 561558.
- Northern Diver, 01257 254444
- Pains-Wessex, 01705 775044.
- Polar Bears Diving Equipment, 01566 776468.
The view
from the
chopper
The distress signal you send up when you find yourself separated from the cover boat may look impressive from your viewpoint at wave level. Likewise the sausage marker buoy and your folding flag. But what do they look like from the search helicopter and from the rescue boat? Are they even visible?
We sent Nick Herbert up in a spotter helicopter to find out which emergency devices deliver the goods.
(Location pictures by Max McLeod.)
BACK on the surface, after an exhilarating drift dive. You and your buddy exchange OK signs over big grins, before rotating in the water as you scan the horizon for your RIB.
The grins fade. You begin to realise just how vast and lonely the sea can be.
What you don't know is that almost as soon as the pair of you went over the side 45 minutes ago, that old engine in the club boat failed. What would you do?
Luckily, our imaginary diving duo have brought a good selection of "attention-getters" along to warn of their plight and guide the rescue units to the right spot. But how well will such devices work when the chips are down?
We asked Portland Coastguard if we could carry out a joint exercise to test diver-location devices in the water, using its Search and Rescue (SAR) helicopter as a long-range "spotter"and its general-purpose boat (GPB) as surface co-ordinator and sea-level spotter.
Organising the exercise was complicated. The Civil Aviation Authority, Poole Harbourmaster, the Police, Fire Brigade, RNLI and local marina operators all had to be notified that something unusual would be going on. The planned date was a Sunday in April that the Coastguard thought likely to be "quiet". It turned out to be anything but.
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SHOUT SOON... If you are in difficulty on your boat or in the water, call for help as soon as possible. The emergency services would rather cancel their lifeboat or helicopter call-out when you are discovered soon than initiate action late and have a bigger area to search. |
On the morning of the day in question a dozen volunteers from Dorset Diving SAC set off on local dive boat Poole Angler for a day out with a difference. Meanwhile, I made my way to the Royal Naval Air Station at Portland, where the photographer and I were briefed and drysuited up. Then we took off, right on schedule.
The Sikorski S61N amphibious helicopter, callsign Hotel Lima, was big inside. Normally operated on SAR duties with a crew of four - pilot, co-pilot, winch operator and winchman - it could carry 19 passengers, so a damp diver or two presents no problems.
As we climbed to over 300m, the first of our diver-location devices was set off by a diver in the water near Ballard Down. At this altitude and a range of six miles, we could hear clearly the Sea-Marshall PLB7 EPIRB (Electronic Position Indicating Radio Beacon) from Blandford Sub-Aqua transmitting its "two-tone" audio signal, and see on the aircraft's indicator which direction to fly to the diver. Even the helicopter crew were impressed.
Just as we were within sight of the diver, a real emergency call came over the radio asking us to help a dive boat in distress. We broke off the exercise and headed for the scene, only to find five other dive boats assisting already. How quiet was this Sunday going to be?
Back near Ballard Down, Poole Angler's captain, Mike Roughton, called for the next device - the 92 Pneu-venture Inflatable Rescue Signal from BCB International - to be deployed.
This device is a helium-filled, radar-reflective balloon which, when inflated by pulling a pin from the gas-cylinder valve, is meant to float up on the end of its 70m tether line and alert ground or ship radar receivers for miles around.
That is the theory. Unfortunately the balloon refused to inflate properly and just dragged along on the surface of the sea. Score so far: one pass, one fail.
| STAY PUT... If you find yourself alone in the water, don't fin. Combining high-tech computer skills, local knowledge and weather information, Coastguard teams can make a fairly accurate guesstimate of where you should be, so don't wreck their calculations. Save your energy and air, and drift with the tide: you will be picked up sooner. |
Next on the list was the 25 Miniflare 3 kit from Pains-Wessex, familiar to many divers.
Operation is a matter of taking the yellow plastic "penjector" from the red plastic case, inserting its business end into the first flare recess and turning it clockwise to engage the lugs on the flare. Pull out the flare, extend your arm, pull back the penjector's trigger with your thumb and release.
A loud crack is followed by some recoil, and the flare is heading for its 80m ceiling. Wait 10 to 30 seconds then fire another one.
The idea of this "paired" discharge is that the first flare should attract attention - even if only out of the corner of an eye - while the second gives a definite direction.
Repeat this cycle with another pair of flares after 10 minutes or so to confirm your whereabouts and that you are in distress, then keep the remaining four flares for when the lifeboat or helicopter is visible.
In our test, the first red flare was fired successfully by the "lost" diver. It was visible at three miles from the helicopter, and a couple of miles from the GPB. But we ran into problems on trying to fire the second flare.
One of the kits slipped out of a wet hand and was lost. We had "waterproofed" another one with silicone grease over each flare end. This had certainly prevented corrosion, but the grease and water meant that the flares were turning in their tubes rather than locking on to the penjector, so could not be withdrawn and fired.
There is a case for Pains-Wessex to provide a length of cord between the Miniflare casing and the penjector - each has a hole for just such a purpose - which could be threaded through a spare D-ring on a BC to prevent loss. Alternatively, they might consider adding two vertical ribs to each flare casing. These could locate in matching slots in each plastic case aperture and stop the flares rotating in their tubes in wet conditions.
Next on our agenda was another Pains-Wessex pyro, the Day/Night Distress Signal (No 1, Mk 4), at around £20. Many divers carry these taped to a knife sheath or in a BC pocket.
Operation is simple. Decide whether you need smoke or flare, identified using the following "memory jogger": the smooth end is for smoke and the knobbly end for night-time. Unscrew the appropriate end cap, point the business end away from you and pull the stainless steel D-ring with your finger.
But before our diver could get this far, we were called away in the Sikorsky to another real shout - this time a kayak had been seen washed up on an inhospitable part of the coast, with nobody in sight.
Hotel Lima was instantly heading for the kayak's last reported position. It was hard to tell which eagle-eyed member of the crew spotted the stranded paddler waving at us from a rocky promontory.
He wasn't happy but he was quite safe, so, after radioing in his position and verifying that help was coming overland, we headed back to our rapidly cooling divers and requested orange smoke.
"Good," was the comment from our aviators when the smoke was spotted, and we afterwards discovered that the sea-level crew thought so too. However (there is always a "but"), everyone agreed that the burn time of around 20 seconds was too short.
The bright smoke gave both location of diver and wind-strength/ direction to our aircrew, and was visible three miles away at an altitude of 100m, although this distance dropped off considerably at sea-level, with wind dispersing the smoke rapidly.
We also had a problem with this dual signal when the diver tried to use the flare end. If you pull the operating tab in the wrong direction, we found, it breaks off in your fingers and leaves you with nothing. Not good, Pains-Wessex.
Moving on from things that fizz and bang, our next test was of Sea-Streak Marker Dye, £13.93 from Advanced Diving Products.
Make sure the pack is attached to your BC with a length of cord through the eyelet - why don't manufacturers supply these? - preferably at shoulder level.
When you need help, pull the white tear seal from the unit and pull the pouch in half. The result is a fluorescent green/yellow stain in the sea said to last up to five hours.
An impressive claim, and it is surprisingly effective. The helicopter crew saw the patch quite clearly 300-500m away, when the dye had only just begun its work.
In an emergency the helicopter flies downtide of the estimated position of a lost diver, then uptide until contact is made. With a dye marker oozing into the sea for such a long time, if the initial search fails the trail is easy to pick up. The marking was also visible from sea level, although not at so great a range. This is another one worth carrying.
At this point we tried the audible signals available to divers, in the form of an air-driven siren, connected between a BC direct-feed unit and its medium-pressure hose, and the good old lung-powered whistle.
Neither was any use at all from the helicopter - which was unsurprising - but the siren could be heard from the GPB at around 100m and the whistle at half that distance.
Conditions were not ideal, with the helicopter's rotor and motor noise and the boat's own engine masking sounds coming from the divers. But we were told that such devices would be excellent in foggy conditions and at night. Lifeboat crews regularly stop their engines to listen when searching in such circumstances.
Getting low on fuel now, we asked for the last three items of equipment to be deployed. These were among the least complicated of our samples, yet proved highly effective.
First out of the bag was the BCB See Rescue Floating Signal Mat, which was pulled from its carrying tube and unrolled into a long, orange marker signal that floated on the surface and was visible from 500m in the helicopter, though it was invisible from the boat. The mat comes in three sizes (5oz £34.15, 9oz £40.99, 22oz £80.45).
Second was the old faithful, a bright orange Surface Marker Buoy of the "sausage" style. This stuck up for itself and could be seen from the helicopter at 700m and from the boat at a quarter of a mile - simple, inexpensive and it works.
But the best was yet to come. Costing the huge sum of £15 or so from your friendly local dive store, one item of safety equipment you should definitely not be without is the Folding Diver's Flag.
The orange flag flies from three plastic pipes that slot together to form a pole, held in position from inside by a bungee cord. It was voted "best of the day" by many of the participants. Visible at three-quarters of a mile from the helicopter and half a mile at sea level, this simple bit of kit cannot be beaten for ease of storage (two straps around your cylinder); ease of use (unfold it, let the bungee erect it, and wave it over your head); and effectiveness.
It is so simple you could make it yourself. It is re-useable. And for night-dives, push a chemical lightstick in the end for increased attention-getting.
Our conclusion was that the best combination of diver-location aids you could carry would be an EPIRB, an orange smoke marker and a folding signal flag.
At nearly £150 the EPIRB is expensive, but it will last many years if looked after properly - including a battery change every year - and will attract a lot of attention when activated.
Pains-Wessex needs to consider the number of sport divers around the world who would buy a long-lasting smoke-only device. It needs to be the same size as the day/night signal to fit in a BC pocket; have a minimum burn time of 60 seconds; have a single waterproof screw-off cap at the business end, with an O-ring to seal it; and have a minimal airspace under that cap packed with waterproof grease. This will ward off corrosion and prevent the cap cracking under normal dive depth pressures.
The trigger mechanism needs to be foolproof, particularly with cold, wet, gloved fingers - the spring-loaded firing mechanism from Pains-Wessex parachute flares, which operate in only one direction, would be ideal. An eyelet or lanyard loop should be moulded onto the handle-end, with a nylon cord loop attached to prevent loss.
Finally, an improved pictogram with instructions is needed on the side casing. The one on our day/night signal was fairly explicit, but failed to emphasise the possibility of misfire if the tab was pulled in the wrong direction.
But until Pains-Wessex comes up with the dedicated smoke signal, many divers will continue to carry Day/Night Distress Signals as a reasonable compromise.
A comment from Mike Roughton makes a lot of sense: "If you are wearing a hood, make sure it has those light-reflective stripes on it." These are standard issue on some manufacturers' hoods, and are available as a sew-on addition from Northern Diver and Polar Bears.
Once fitted, they make a diver's head - normally a small target in dark waters - visible from 200m away at night, when the helicopter's searchlights are switched on.
Another thought: our winchman for the day, Bill Deacon, posed the question: "Why do diving and safety-gear manufacturers make their SMBs, warning flags and so on from orange or red-coloured fabric, when fluorescent green-yellow shows up at twice the distance?"
So, Mr Manufacturer, how about a colour change for all such devices?
There is one other method of attracting a helicopter when all else has failed. SAR helicopters have rather clever equipment on board called Forward-Looking Infra Red (FLIR), which enables the crew to locate heat sources in cold surroundings. The heat sources appear as white blobs on the monitor screen, and our crew was able to spot the return of our bare-headed diver at a distance of 400m.
But we must stress that this was carried out as a test, with the diver entering the water with hood on and removing it only briefly until detected. You decide if you want to rely on FLIR.
The sea-borne phase of our exercise over, all we had to do was transfer from helicopter to dive boat at sea - an exhilarating ride down on the winch - then return to the quayside at Poole for debriefing and an evening pyrotechnic display, a joint venture on behalf of divers between the Royal National Lifeboat Institution and the Coastguard. My sincere thanks to them and to everyone who made this exercise possible.