DIVER TESTS

December 1996


Do me a Favor!
Air-integrated deco computers are the most important technological advance in diving safety, says John Bantin, who welcomes a new arrival from Suunto.

Suunto Favor Air Lux Running out of air is what every diver strives to avoid, but why does it happen? Putting aside major high-pressure hose failures or blown O-rings, which tend to happen when a tank is at its highest pressure at the start of a dive, the finger can normally be pointed at poor air management.
Air-integrated computers neatly remove air management from those ill-equipped to do it accurately and, using a diver's actual breathing rate, ambient depth and remaining tank pressure, calculate an estimated "remaining air-time". This is displayed alongside the minimum safe ascent time (including any stops that may be needed). Should this "time to the surface" exceed the remaining air-time, it will not require Einstein to see that problems loom.
I believe that air-integrated decompression computers are the single most important technological advance in diving safety. I now feel insecure diving without one. Naturally, these devices have been positioned at the most expensive end of every manufacturer's product range. If you want air-integration it seems you also need all the other bells and whistles.
Another feature of top-of-the-range computers is the ability to interface with a PC, so that the user can spend enjoyable hours at home going over previous dive profiles, presumably as an alternative to surfing the net.
Now I am one of those dinosaurs who think that "netsurfers" are today's equivalent of trainspotters, albeit without those blue anoraks with orange linings. I am a PC-illiterate. After the novelty value of my first printed-out dive profiles had worn off, I never wanted to see another. I am too busy diving! Suunto, appreciating that there are still people like me around, produced a full-function computer without this PC-interfacing feature. It is the Favor, and now you can have it air-integrated in the form of the Suunto Favor Air Lux .
Connected to your regulator by an hp hose, it displays tank-pressure readings with remaining air-time and, initially, remaining no-stop time. Audible alarms are activated once tank pressure drops to 50 bar and 35 bar respectively. In addition, the remaining air-time display is flashed once you are low on air.
Once you run out of no-stop time, a total ascent time is displayed together with the depth of the deepest stop. This allows for an ascent rate of 10m/min, which is controlled by an indicator which moves between three green (OK) and two yellow (too rapid ascent) sections. Beat that and the word "SLOW" comes up.
When you are into deco stops, an upward arrow is displayed. Reach your first stop depth and this turns into a wine-glass shape. Ascend too far and you get a downward-pointing arrow.
Other displays include the actual depth, water temperature (alternating with maximum depth achieved), and dive duration. This Suunto, like its siblings, uses an algorithm based on a Haldanean table, modified with Dr Spencer's research into silent bubbles. It uses eight tissue models. There is three-level user adjustment too, which can be used either to allow for altitude diving or for personal caution.
Display at the surface includes all the normal things like surface interval, maximum depth of the last dive, whether flying is not recommended, total desaturation time, time, date, current temperature, and whether there was anything wrong with the diver's decompression activity during the previous dive. The logbook function remembers nine dives.
The Suunto Favor Air Lux also has a built-in calendar/clock so that time is always indicated, even when the device is switched off - with no additional battery power consumed.
The Suunto uses a 2500 hour lithium battery that can easily be replaced by your dealer when the time comes.
Why the "Lux" suffix? Suunto has developed a remarkable illumination system using electroluminescent film, and both the Eon Lux and Favor Lux are fitted with this useful feature. Gentle pressure on the right-hand side of the computer body causes the screen to emit a blue back-light against which all its information is clearly readable.
The Suunto Favor Air Lux sent to me to try was installed in a console together with Suunto's SK-7 compass. It makes a neat package.
It has a card that is easy to read even when tilted quite far from horizontal (something that often happens when you are without a horizon under water) and also has a window that allows you to read off bearings directly when sighting your course. The Suunto Favor Air Lux costs £350 complete with compass.


Fl'air of the French
Like Jacques Cousteau, Beuchat diving equipment comes from France. Unlike that famous pioneering diver, Beuchat seems quite coy about generating any publicity for itself in Britain, but I can assure readers that the marque is well known worldwide. Beuchat V4 and V8 regulators Our recent regulator test (Diver May/June) featured the Beuchat VS10. Since then I have had the chance to try the cheaper VS8 and VS4 models.
The VS8 has a balanced diaphragm first stage with one high-pressure and four medium-pressure ports arranged radially around it. This does lead to ungainly hose routeing or even hose kinks, unlike the turret-version VS10.
Otherwise I found the VS8's performance very much in line with that of the VS10 we had previously tested, although it did not arrive in time for our side-by-side ANSTI machine maximum depth rating test. Beuchat provided its own test graphs to show that its regulators are all good for 50m diving. Both the VS8 and VS4 have EN250 certification, as does the VS10.
The VS4 has a first stage remarkably similar in appearance to the Oceanic Balanced Piston first stage that did so well with the two Oceanic regulators tested. This likeness is further underlined by the news that Beuchat now supplies it with a similar satin chrome finish.
The regulator has four mp and two hp ports.The mp ports are arranged around a turret that, unlike the squat one on the VS10, is tall enough to clout you on the back of the head during some part of the dive unless it is mounted inverted on the tank valve. This is a common problem with tall turret designs.
The second stage is common to all three regulators. It is rather unfashionably large and has a breathing-adjustment or detuning knob for those who think the regulator breathes too easily. The mp hose is integrated with the second stage by a bulky shroud which gives that part a rather heavy appearance, belied by its actual weight.
Roberto Bagnasco, an intrepid Italian-Swiss technical diver friend of mine, uses Beuchat regulators. He has regularly dived to 120m using various gas mixes and when I last saw him was planning a dive to 160m involving seven gas switches. He obviously has confidence in the product. The maker offers its first stages with the option of a DIN tank-connection with such divers in mind.
The Beuchat VS4 costs £159.95, the VS8 £154.95.
Wizard for rough seas
An Electronic chart system is one of the best navigation tools for boat divers, but trying to get one that works properly in a RIB is another story, writes Dag Pike.
It needs to be rugged, reliable and, above all, readable when the boat is bouncing around at sea. Using such a system on a racing RIB is in many ways the ultimate test and the Lowrance Global Map 2000 has survived half a season of tough racing without a problem on one of the fastest RIBs on the circuit, the Royal Marines' Blue Water Maritime boat, powered by twin 200hp Mercurys. We know it is rugged and reliable - but how easy is it to use?
If you are familiar with basic electronic navigation terms you should have no problem, even without a handbook. A GPS is integrated into the unit to produce continuous position-fixing, and even with the antenna mounted close to the engine the signals are good and reliable. The display itself is waterproof but the separate chart reader where the cartridges are inserted is not, so needs to be mounted in a protected area. The 2000 takes the comprehensive C-Map cartridges, but if you move out of range of one of these you need to switch it, which probably means stopping to get access to the unit.
The 2000 is largely menu-driven, using the buttons to the left of the screen. Most of these are dedicated and throw up a list of options. The top two "zoom-in" and "zoom-out" to adjust the chart scale, which is a bit confusing. Getting the unit to follow a track to a waypoint takes a bit of playing with the buttons and menu to obtain the correct result, but once organised is very practical. The monochrome display is on the small side but compensates by being sharp and clear. The chart, which can be combined with an information panel, is the primary display but push-buttons below the screen allow you to select alternatives such as the excellent steering display. This shows graphically where you are in relation to the next waypoint and is combined with digital information of a size that is easy to read even at high speed.
Like all electronic chart systems, the 2000 would benefit from having a larger screen, but within the practical limitations of size and cost, it is a good enough solution.
To the right of the display is another button panel used for entering positions and to control the cursor. These buttons are small and less easy to use, and the frequently used ENT and CLR buttons are not well-placed. However, if you have the unit set up before you leave harbour there should be little need to play with these controls.
One version of the 2000 incorporates an echo sounder, the Lowrance speciality. The high-quality display can occupy the whole of the screen, or share a split-screen with the chart. Lowrance offers a special sounder transducer for fast boats, which could make this unit ideal for divers who want a single unit to tell them where they are and what is beneath them.
The Global Map 2000 costs £893.
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