TRANSMIT CONFIDENCE

John Bantin tests a new system for keeping divers safe - but will the dive-boat operators buy it

Arent you going to fasten your seatbelt
I asked my Indonesian driver.
Why should I he retorted. Im not going to have an accident.
This neatly sums up all safety equipment. If regulations didnt force us to have them, wed happily do without.
There was a time when not one Egyptian dive-boat used RIBs to pick up divers. They would instead reverse the liveaboard vessel up to divers who surfaced by the reef.
Can you imagine how dangerous this was No one had any small inflatable boats, and the boat-owners couldnt see why they were needed. Then the better-class Egyptian boats started to use them, and now its normal practice.
I would hope they all have life-rafts and life-jackets now, too!
The German manufacturer of the ENOS would like to see every dive-boat equipped with its electronic diver locating and recovery system, but it is having an uphill struggle persuading boat-owners to spend the rather large sums of money involved.
In Egypt, with boat-owners smarting over the recent rise in the price of their government-subsidised marine diesel (although it is still one-tenth the cost of marine diesel anywhere else in the world), they are hardly likely to want to splash out. After all, theyre not going to lose anyone, are they
Would you pay a surcharge to book onto a boat that had such safety equipment To buy a search unit and sufficient transmitters to equip every diver on board is expensive, but I took a set to Egypt and tried it out during my voyage on a liveaboard dive-boat.
I chose Egypt because, along with European countries, the Maldives and the Seychelles, the ENOS System 869 operates with a radio frequency that is permitted in Egypt.
It is licence-free, and its use does not have to be reported to the appropriate authorities of these countries.
The system works in conjunction with GPS, which is operated by the US government. It works independently of any international rescue service, and as such has no operational charges attributed to it.
Each diver carries a transmitter that is activated at the surface only in an emergency. The boat carries a receiver unit that must be switched on the whole time the divers are in the water.
In the event of an emergency signal being put out, the receiver emits a loud noise, indicating to the boat crew that a rescue is needed.
At the same time, the transmitter carried by the lost diver determines its position by GPS and transmits this to the on-board receiver. The receiving unit then calculates from its own GPS position the distance and direction of the emergency signal.
Only ENOS receivers can receive signals from ENOS emergency transmitters. However, if boats equipped with such receivers are in the area, they will all receive the signal.
The system is autonomous in that it has its own power supply and does not interact with any other rescue system (as, for example, an EPIRB does). The independent power supply means it can be used in a small boat such as a RIB.
Rather like VHF radio, it works by line of sight, and has a range of around 3km in a small boat. By positioning a separate antenna high up on the main vessel, it is claimed that the range of the ENOS system can be extended to 10km or more.

THE LOST DIVER AT THE SURFACE will have been carrying the transmitter in his BC pocket or clipped to his kit by its lanyard. He switches it on by twisting the base (and possibly breaking a seal), and holds it as high above the waves as he can while it triangulates on three satellites.
Once it has done this, it sends the emergency signal and position to the receiver unit back on the boat. There is an indicator LED on the divers unit, but it is not necessary to observe this.
Provided the helmsman remembers to steer around obstructions such as reefs, he can head directly to where the lost diver is positioned.
If a group of divers have had an incident which results in them coming up all over the place and sending emergency transmissions, the receiver unit can log them all. These logged transmissions are deleted only once the divers are safely back on the main vessel.
I tried ENOS while aboard my Miss Nouran in the Red Sea. The receiver unit was connected to a VHF aerial rigged high up on the boats cross-trees to give it as much range as possible.
You can use a small aerial attached directly to the unit in its watertight case, and this might suit small boats, although a dive clubs RIB could have the larger aerial rigged to its A-frame. The GPS aerial needs only to see the sky.
My first problem was that Miss Nourans RIB coxswains were too efficient at picking up surfacing divers. The safety beacons were held up above the water and the receiver unit squawked that there was a diver who needed rescuing, but the diver was always out of the water before a unit could have time to triangulate on the required three GPS satellites, so no position was transmitted before the unit was switched off.
I decided to send someone out in a RIB. If you were really lost, you would give the ENOS transmitter plenty of time to lock on. In the event, it took about four minutes for the divers beacon/transmitter/GPS to lock onto the required number of satellites and then it worked sweet as a nut.
The transmitters position relative to the receiver on the main vessel was given as a bearing and as a distance. It was simple. Because the information is transmitted by radio, the range of the unit is limited by the curvature of the Earth. The higher the receiving aerial is positioned, the further it can see.
The divers unit is slightly buoyant, so in a worst-case scenario it could still bob in the water and do its job.
Like any emergency equipment, you install it hoping you never have to use it. Its not for routine diver pick-up. Its an expensive system but I, for one, would feel more confident booking onto a dive-boat that used it.

GROUPS OF DIVERS travelling to Egypt have the option to rent the equipment from the local delivery agent and take it on board with them, but they must be sure that someone who knows how to use it is always with the receiver unit while they are in the water.
A receiver unit and six emergency transmitters costs 500 euros to rent for a weeks trip - 200 for the transmitter and 50 each for the receivers, plus deposit - thats about 66 a head.
A boat operator buying the ENOS system would pay 2980 euros for a receiver and 7400 for 10 transmitters.
Thats well over 8000 plus sales tax, custom tax and delivery, so you can imagine why they might hesitate.
My thanks to Rahim Hamada and Captain Tarek from Miss Nouran, plus divers Andrew Ware, Tim Bagnall, Andy Earnshaw, Stuart Yates and Simon Rispin from Cold Bath Divers in Yorkshire for helping me with the research for this feature.

ENOS is made by Seareq, www.seareq. de. The rental service, also in Germany, is Dive It, www.dive-it.de


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The diver holds the ENOS transmitter as high above the waves as possible.
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The receiver must be on all the time while divers are down.
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A diver with the ENOS transmitter unit
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the receiver antenna mounted on the boat
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the receiver unit controls and display