• Diver shall speak unto diver - US Divers Buddy Phone
• Two more from Aladin - Aladin Air and Aladin Pro Nitrox
• Tekky tips - Lumb Bros. Jon Line and Slate

"I suppose you are going to show me a big green moray."
"I do not know if there is one here. Would you like to see a frogfish?"
"Yes, please."
"I cannot see it."
"What colour is it?"
"Yellow."
"Well, I still cannot see it."
"Never mind, I will show you our tame octopus."
"Say again."
"I will show you an inkfish!"
"OK!"
"It is not here either. Sorry!"
"Never mind. What do you think of the Buddy Phone?"
"I find it best to hold it in position firmly over my mouth to keep it watertight, but my mask keeps leaking."
"That is because you have some hair caught in it."
"Thanks. Look at that scorpionfish. It makes a perfect picture."
"I know, but I always see these things when I do not have my camera with me."
"I seem to use lots of air because I keep having to clear my mask."
"Get rid of the hair!"
"Swim away from me and we will see if we can still talk." "Can you hear me now?"
"Yes. You are about 20 metres away but the sound is softer." "What did you say?"
"The sound is not so good!"
"You sound like you are shouting at me from the end of a large room. Stay there. I will come back."
"If you are looking for me, I'm above you. I am down to 50 bar."
"If you want some air, I still have plenty. I have got 100 bar." "No, I would rather go back."
"OK. Thanks for a nice dive."
"It was my pleasure."

The US Divers Buddy Phone takes some getting used to. It is a bit like talking to the Flying Doctor from Wollamboola Base. You have to use a press-to-speak button on the side of the mask. You must also ensure that your buddy is listening. When he is blowing exhalation bubbles, the noise will blot out incoming messages.
Your words need to be chosen with care, too. "Inkfish" reads better than "octopus". Italian is less comprehensible than German. The conversation above was between me and a Dutchman. I found that the HM-2 mouth mask had a tendency to flood if I looked down, or bumped it against my camera housing while looking through the viewfinder. Without a good seal around the mouth water will rush in, so you will inevitably use the purge button more than usual.
I got round this by holding my mouth in a "whistling" position when not speaking. Of course, there is nothing in your mouth, because the mouth mask replaces the usual regulator mouthpiece. You have to mount it before putting on your conventional diving mask. Should you get into difficulties, you can always pull it away and substitute your octopus second stage.
The effective internal volume of the regulator second stage is increased by several 100 per cent by the mouth mask, so a regulator tuned for normal use will tend to free-flow. I was supplied with the units each attached to a Spiro Supra XR2. I found that their breathing-resistance control knobs needed to be screwed down to the minimum, and their venturi levers positioned in the minus position.
Each unit runs from a PP9 battery and is activated when immersed in water. However the batteries are easily removed and I took them out between dives.
The Buddy Phone is available as a receiver unit only. This requires no skill - just clip to the mask-strap and listen. Ideal for models underwater!
We found it amusing to take one diver equipped with a receiver unit only along with two other divers equipped with transmitter/receivers. The one without the transmitter was reduced to silly-looking hand signals - just like a normal diver.
The Buddy Phone is a lot of fun but has plenty of serious applications. The Health & Safety Executive is recommending that comms equipment be used whenever divers work under water. Taking the photograph to illustrate this piece was remarkably easy, for instance, because I was able to tell my models exactly what I wanted them to do. I had a roll of film shot in about two minutes!
The US Divers Buddy Phone Transmitter/Receiver unit with HM-2 Mouth Mask costs £449. A Receiver Only unit costs 231. There is also a Surface unit with a hydrophone, useful in commercial situations. This has a small speaker built in but I would recommend headphones, not included in the basic price of £1355.
And remember, buying a single unit leaves you with no one to talk to!

Aqua-Lung UK, 01162 514200

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Two more from Aladin
AIR-integrated decompression computers are designed to ensure that a diver does not miscalculate his air requirements or mismanage his air supplies. By displaying "remaining bottom time" (RBT) a diver knows exactly how long he has to get to the surface before either his air supply or no-stop diving status runs out. And, for a decompression-stop dive, he knows how finely he is managing his air by comparing his RBT with the "total time for ascent". The first enterprising makers of air-integrated computers tried linking the computer to the air cylinder using a high pressure hose to replace the hose of the conventional pressure gauge. However, when the regulator was dismounted from the tank it did not always get the tender loving care needed for the computer, which was still attached.
More recently, manufacturers have used a radio-controlled link from a transmitter mounted in the hp port of the regulator to a wrist-mounted display unit.
The Aladin Air X, Monitor 3, Mares Genius and Oceanic DataTrans are popular examples of this genre. The wrist unit can be kept separate in case the regulator with its small transmitter unit is dumped into a bucket of water by a helpful deck-hand. However, this higher level of technology costs - a wallet-bending 624 for the Air X. There is also a measure of uncertainty regarding the use of wireless equipment, as you cannot see it working.
The Aladin Air (without the "X") bridges the gap. It is connected to the hp hose, but the end with the console can be instantly removed via a bayonet connection once the rig is depressurised. This removable console also carries a compass (conventional or Uwatec True Track), so all your instrumentation can be in one package.
The Aladin Air gives you the same information as the more expensive Air X. In some ways I preferred it, because although it lacks the jazzy anatomically designed casing of the Air X, which wraps around your wrist, it puts the air information more logically alongside the decompression information - just like the Monitor 3 and Genius.
This means that you do not have to rotate the instrument to get all the basic data during the dive. Displayed are: current depth; dive time elapsed; maximum depth achieved; remaining no-stop time or stop time at the first required deco stop; time to the surface (including required stops); remaining tank pressure; and remaining bottom time based on tank pressure, ambient depth and previous breathing rate. There is also a clear graphic representation of the amount of air left.
Ascent rates are displayed in percentages of the maximum allowed (they vary to a slow 7m/min as you approach the surface) along with various audible alarms and visual warning icons.
Once you break the surface, total desaturation time and an adjusted "time to fly" is displayed.
Between dives you can amuse yourself by examining details of the past 19 dives in logbook mode, or plan dives in plan mode. These modes are activated by wet-finger contact with the appropriate pair of the four contact points available.
The Aladin Air can interface with a PC using Datatrak for Windows and the new Memo Mouse, which allows you to examine the details of dives logged. You will need Datatrak version 1.7, which Uwatec UK will supply free to Aladin Air owners who own an earlier version.
The Air will work with cylinder pressures up to 350 bar. Like all recent Uwatec computers it uses the latest Buehlmann ZH-L8 ADT mathematical algorithm with an eight-tissue model representing tissues with half-times from 5 to 640 minutes. This algorithm takes into account provocative diving practices such as yoyo profiles, cold-water conditions, increased breathing rates indicating increased muscle loading, and repeat diving with short surface intervals. This is reflected in the longer deco stops required on current and subsequent dives. The display shows "Atn" if the diver has undertaken dives that might have caused microbubbles to be produced, and "SoS" if he has missed a required stop. During a three-week trip on which I was repeatedly diving for two days and making a short flight to my next destination at the end of the third, I saw "Atn" displayed a couple of times.
The Aladin Air slots in between the Pro and the Air X in the Uwatec price list. At 460 with conventional compass, it is an example of the best diving computer technology at less than the most expensive price.
Another fairly new Uwatec computer, the Aladin Pro Nitrox, is for the nitrox diver who wants all the benefits of a nitrox-compatible instrument but cannot afford the air-integrated Air X Nitrox, Uwatec's top-of-the-range computer.
The Pro Nitrox is a nitrox version of the popular Aladin Pro. It is not air-integrated, but otherwise has all the decompression features of the Aladin Air.
Its defining characteristic is the ability to modify its calculations to suit any mix, from nitrox 21 (air) to nitrox 50. This is easily preset before the dive so that the diver can get the maximum time underwater.
An alarm sounds if the diver reaches a depth limit, which can be preset using the Datatrak PC interface and Datatalk software. The computer comes from the factory set at a depth representing 1.5 bar ppO2. It also has a built-in oxygen clock that adds Oxygen Toxicity Units to prevent the diver being over-exposed. Datatrak version 1.6 or higher is needed to work with Aladin Nitrox computers. When the optional external memory Memo Mouse is used, version 1.6E is required. For those who already own the hardware but are upgrading to nitrox versions of any of the Aladin computers, Uwatec UK will supply a copy of the 1.6E program disk free.
The Pro Nitrox costs £365. Like the Air it uses a lithium battery that can be replaced only by a qualified technician, normally at the distributor.

Uwatec, 01420 561 412

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Tekky tips
Like many others during the 1980s, I was a technical diver but did not know it. I was using a twin set with manifolded cylinder valves and independent regulators, using a back-up computer to my main diving computer, and doing dives that needed lengthy decompression stops.
So long were these stops that even in the gin-clear Mediterranean where I mainly pursued my hobby, things got a bit boring. I perfected the technique of turning the pages of waterlogged paperbacks. It worked so long as I was never tempted to read them between dives.
The main problem was keeping to my station while not constantly monitoring my depth. So I devised a simple system of karabiners spliced into the anchor warp of the dive boat and clipped myself on at 9m or 6m. This worked well enough but got a bit hair-raising if the boat was subject to big swells.
Unknown to me, in the USA one Jon Hulbert had devised an answer to this problem. It is now well-known to tekkies as a "jon line".
It takes the form of a short length of 2.5cm webbing with a karabiner clip at one end to attach to the diver. The other end has a uniquely designed spring clip that jams easily over a main ascent line such as my boat's anchor warp. Attach it where you like.
The metre of slack line acts as a damper, taking up any movement transmitted from the surface.
You can buy a ready-made Jon Line made by Lumb Bros for £17.99. I tried one and found that I was able to doze without any head-snapping jerks disturbing me.
Another improvised gizmo I have seen tekkies using is the curved deco information slate. This was generally cut from a white plastic pipe, the sort used in larger-bore plumbing, and strapped around a forearm.
All the essential deco stops and gas switches are clearly marked out and the slate's location means it is always close to hand! Lumb Bros now supplies a purpose-made Computer Wrist Slate. It is retained on the forearm by the straps of a diving computer and comes in two sizes to suit virtually all the computers on the market. A clipped-on pencil is included. Essential for those with complex dive plans, the slate costs £7.95 in either size.

Lumb Bros, 0161 681 5790

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