April 1999

John Bantin has been a full-time professional diving writer and underwater photographer since 1990. He makes around 300 dives each year testing diving equipment.

Tutor computer could suit'ya

• Tutor Computer could suit'ya - Mares Tutor computer
• Bright green fish-frighteners - Unidive fins
• Strong winds of the Millennium - Poseidon Triton Millenium reg.
• Want d-rings? you got 'em! - Northern Divers Guardian BC
• Kite finally makes its mark - Skystreme emergency kite

The Mares Tutor, a diving computer made exclusively for that company, joins a long line of new products that spring from an extensive research and development programme. Following in the footsteps of the Genius (an Aladin Air X in Italian clothing) and the Guardian (a computer that, although worthy, was rather on the large side and showed teething troubles on early versions), the Tutor is a neat wrist unit with a very readable display.
Like many of the latest examples of dive computer wizardry, it has several modes of function, including the ability to tell you the date and time. Besides clock and dive modes, it has modes for dive planning, simulation, logbook and variable settings. It can be individually set up by the user for three different altitude ranges and metric or imperial units.
Two wet metal contacts start it automatically in dive mode, but it is otherwise accessed via two easily used yellow buttons - so no more frantic finger-licking!
Most importantly, it runs on a user-replaceable AAA battery that can be purchased almost anywhere, and is said to be good for three months or 50 diving hours. The battery compartment is made watertight by an O-ring but is separate from the rest of the computer, so if you do flood it, the damage is repairable.
This is a full-function decompression-stop diving computer with a nine-tissue model modified Haldane algorithm. Using it alongside a Suunto (about the most cautious computer around), I found that the Tutor seemed to allow me a slightly faster ascent and a tad more no-stop time.
However, like the Guardian, it has a little trick up its sleeve once you get up to the 5m mark. You might still be into no-stop diving at this stage, but it suggests you make an additional three-minute safety stop between here and 3.5m. This is shown on the display by a large "St3" (reducing to "St2" and so on). Taking this into account put it very much back in line with the Suunto's caution, although in a typically Italian way it will allow you to ignore this phase without telling the world that you have done so!
There are audible alarms for the violation of a deco stop; if the battery is low; when you run out of no-stop time; or if you ascend too quickly. The Tutor has a variable ascent-rate indicator that allows you to ascend at 18m/min up to 20m, 12m/min up to 10m, and 10m/min from 10m to the surface.
The Suunto with which I compared the Tutor has a fixed rate of 10m/min from any depth, and I was anxious not to violate this speed limit. However, I was surprised to find that, when I recalled my dives in logbook mode, on several occasions the Tutor reported me as making a fast ascent.
Perhaps it was caused by those last few feet of water when I struck out for the ladder of the dive-boat. No such fast ascent was recorded on the Suunto, which was always alongside the Tutor.
Once you get into deco-stop diving, the Tutor becomes quite noisy, with a long series of audible warnings. It then shows the depth of the first stop, time required to wait, and total ascent time needed.
After the dive, the Tutor records any action it has been programmed to think is provocative. This includes such things as a repetitive dive conducted less than two hours after a previous one; one deeper than the previous one; one of more than 30m; a deco-stop dive; or one with an excessive ascent rate. These show on the display as a discreet set of asterisks.
The Tutor keeps track of residual nitrogen times and time-to-fly. It also records details of your past 20 dives, which are readily obtainable by pressing the buttons appropriately.
Data retained in the logbook includes maximum depth and duration of each dive; date and time; any outstanding error messages; and minimum water temperature.
You can try all this before you dive simply by operating the unit in simulation mode. I felt confident in the information the Tutor gave me, and didn't tear any hair out trying to retrieve dat about dives afterwards.
Like most top-of-the-range computers nowadays, this one can be interfaced with a PC for downloading info on dives.
Although it does everything you could want from a non-air-integrated, non-nitrox computer, it is priced at the lower end of the dive computer price scale.
The Mares Tutor costs £190.

PLUS	MINUS
+ Clear display + Optional safety stop + Ordinary AAA battery + Economic price	- None apparent

Blandford Sub Aqua 01923 801572


Bright green fish-frighteners
Lurid - that's the only way I can describe the colour of a pair of fins sent to me to try by Northern Diver. Fluorescent green might be thought of as a "safety" colour, but it certainly alarms the fishes!
It was a pity, because these fins proved exceptionally good at powering me through strong tidal currents running against me in some of the offshore caves in the Mergui Islands of Burma.
Perhaps it was because they were playing at home. For these Unidive fins are made not so far away in Taiwan, the place that has taken over from Japan, since WWII, as pre-eminent in drawing on existing design elements to come up with cheaply priced products for the world market. In this case, it might be argued that these fins look not dissimlar to Typhoon Cutters
These Unidive fins are made from three different materials. The blades are mainly of a compliant plastic, which bears the main colour.
Integrated with this, the even softer rubber-compound foot-pocket extends, with a malleable ribbed section, the length of the blade. The whole thing would be very floppy but for two rigid struts of hard black plastic that give the fin a resistance to flexing along its length.
The overall effect is to cause the fin to flex across its breadth when under load, which seems to achieve the "spooning" effect sought by so many modern fin designers.
In the size XL supplied, the foot-pocket sucked in my boot very snugly, its base encompassing the sole of my boot right up to the heel.
In short, the fins became part of me, as the very best Italian brand-leading fins do. There was no hint of wobble or shift when it came to doing some urgent finning.
My only reservation was that the fin straps felt too soft. I had little confidence in their longevity, and it would seem no big deal to substitute these for a tougher pair.
The other point was that the quick-release buckles, although of a simple and robust design, seemed to be made of rather rigid and hence brittle plastic. I am not sure how long these would last in the combined rigours of regular use and tropical sunshine.
I would suggest that these are a viable alternative for those who want Italian performance but are not prepared, or dive too infrequently, to pay top-dollar. I would choose a different colour, however!
Unidive fins are available in sizes M, L and XL and in blue, black, yellow and green.
They cost £40 a pair.

PLUS	MINUS
+ Good "spooning" action + High quality of manufacture + Economically priced + Comfortable fit	- Buckles and straps may be fragile

Northern Diver 01257 254444


Strong winds of the Millennium
Twentieth Century Fox thought it had a very up-to-the-minute name until the millennium hype took off. Poseidon might equally rue the day it named its new regulator the Triton Millennium. I fear that by 2005 it might sound rather old-fashioned!
The press release from its importer, UWI Circle, poses the astute question: "Why does everyone talk about joules/litre, litres/minute, mm vp and the like, when all divers want to do is go diving and rely on a regulator to give them the air supply they need?"
The diaphragm first stage looks very much like that of all the other Poseidon regulators, with four medium-pressure and two high-pressure ports and a DIN fitting combined with Poseidon's standard A-clamp adaptor. It has a slightly reduced flow-rate compared with its established stablemates.
What Poseidon has attempted is to take a design popular with the deep-diving technical fraternity, and combine it with a second stage that will appeal to the ordinary leisure diver.
The Triton Millennium's second stage is what's new. It is made of lightweight plastic, sealed at the factory, and can be used any way up, from right or left. It is just what you need in the panicky moment of an air-sharing manoeuvre - if it's a real emergency.
This Triton is a complete redesign of the previous one. The low-pressure mechanism is a sealed unit that now uses a servo tip rather than a lever, the part that probably caused problems in the past because of a build-up of salt crystals and detritus. I am informed that servicing will be no more expensive than for any other regulator.
Poseidon regulators have a reputation for being able to deliver vast amounts of air. Because of the nature of their servo design, this is not always done in a very measured manner. You either have a lot of air or you don't. The Triton Millennium's second stage is so lightweight at 85gm that it hardly notices in the mouth - until, that is, you have cause to inhale. Then the trap-door opens and you get at least as much air as you wanted. I experimented by taking tiny sips of air, but was rewarded with a fluttering effect that I found less than pleasant.
And it doesn't stop at the point of inhalation. Press the purge button, an item cleverly disguised within the groovy avant-garde design of the plastic unit, and you risk turning that little wobbly bit at the back of your throat into something resembling a granule of freeze-dried coffee!
It seems there is a distinct group of divers who want things that way. They probably drive cars with massive pushrod V8 engines, too.
I once owned a high-performance car that was marred only by the small size of its fuel tank. I spent so much time on cross-continental runs making refuelling stops that I lost any advantage from its overall performance. The same is true of regulators. Make sure your tank is big enough to match such a huge delivery of air.
Technical divers who go in with a travel mix, a bottom mix and a decompression mix usually carry a lot more gas than they need. If you can carry three cylinders, why not take extra? It's part of their philosophy.
Regulators that deliver gas in a rush suit many tekkies' style, and that's why this type of regulator with a servo design proves so popular among them. And with so many regulators to choose from when rigged with multiple tanks, the opportunity to use one either right- or left-handed is a boon.
So if you are a gas guzzler and it is massive amounts of air that you feel you need, look no further - this is for you.
The Poseidon Triton Millennium costs 292.

PLUS	MINUS
+ Vast quantities of air + Use it right or left-handed, either way up + High-performance pedigree	- Delivery of air can be violent

UWI Circle 01420 544795


Want d-rings? you got 'em!
Word on the street had it that Northern Diver's Guardian BC was not CE-marked. Word was wrong. Perhaps that's why this crucial sign of compliance with consumer standards, together with EN1809 and EN250, is emblazoned so visibly on the velcro epaulet of the BC's corrugated hose.
The Guardian is of a conventional design, with a hard backpack and cushion. A single camband secures the tank, and the adjustable cummerbund is secured by velcro plus two helpings of webbing with fastex buckles. The Guardian is smothered with large, stainless-steel D-rings. I counted 12!
The two side-pockets are capacious, and there are several hose-retaining clips, including one of a design new to me, which stops hoses slipping along their length.
Many club divers would not dream of diving without a 400ml auxiliary air cylinder, so there is provision for this, though the example sent for me to try did not have one.
I liked the way the direct-feed hose clipped away easily behind the BC's corrugated hose, which came with a power inflator and an emergency whistle powered by medium-pressure air. I half-expected some confusion over which button to press for inflation, but there was no problem.
Deflation is simple - pull down on the corrugated hose to operate the shoulder-mounted dump valve. This always seemed to be in the right position, and I had no trouble expelling all the air as I ascended. Why can't all BC manufacturers get this part of the design right every time? There is also a bottom dump should you need it.
The N-Diver Guardian BC is a design from the no-nonsense school of thinking. It makes a good club jacket and could not be faulted in the way it does its job. If I have a criticism, it is that it could be a little dull, especially when one has the problem of writing about it!
The Guardian BC comes in sizes S, M, L and XL. In size M it has a maximum lift of around 22kg.
It costs £225.

PLUS	MINUS
+ Novel clip design + Workmanlike and practical + Sensible inflation and dumping + Generous supply of D-rings	- Unexciting - Compulsion to buy items to hang from all those D-rings!

Northern Diver 01257 254444


Kite finally makes its mark
When our Managing Editor tried the Skystreme emergency kite or radar-reflective Personal Location Marker late last summer, it proved a dismal failure (Diver Tests September 1998).
Not intended solely for divers, it got rave reviews in other quarters but the difficulties Steve Weinman encountered were important enough to persuade the manufacturer to modify its design. The problem? He couldn't get it to fly once it was wet!
Apart from ancillary uses such as improvising a thermal vest by stuffing it up your jumper, or employing it as an emergency inflatable first-aid splint, I am sure most divers would buy one for that day they hope will never happen, when they are lost at sea.
The idea is that it becomes a highly reflective inflatable kite which a lost person, in our case a diver, can fly to become a larger, more reflective target for the radar of anyone searching for him.
This time I employed the services of Steve Weston of the new Wraysbury Dive Centre. He tried flying it while bobbing at the surface of the training lake near Heathrow. There was a breeze (there always seems to be a breeze at sea) and, with the help of a buddy who launched it into the air, Steve managed to fly it quite easily.
Whether it would be seen by any radar is another matter, but was it a coincidence that we noticed a couple of 747s that had just left the runway veer sharply away as they approached the Wraysbury lake?
We had the usual difficulty in tearing open the foil packaging, and immediately lost the drinking straw provided for letting air out in case you over-inflate the Skystreme kite, but Steve Weston's opinion of its effectiveness was delivered in a single word: "Brilliant!"
That was because he evidently had a lot of fun flying it. I would suggest, however, that if you intend to carry one of these items against the day you need to use it in earnest, you buy two. Battling with the wrapper and the instructions at a time of crisis could result in further frustration.
Use the other one for a practice run first. Kite-flying is a very relaxing and therapeutic pastime.
The sealed pack floats, which is useful at the surface, but you must stash it away well within your BC. Otherwise I fear that on the day you need it, you will find that your Skystreme pack has joined the other flotsam and jetsam of our world, somewhere in the sea.
It costs £28.

PLUS	MINUS
+ Worth having in case of emergency + Multiple applications + Therapeutic! use	- You need to practice, and that costs

Orbic 01795 52178

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Appeared in DIVER - April 1999

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