February 1999
Wings of progress
There are still pockets of resistance to the use of wings by leisure divers - some say they pose dangers.
But according to John Bantin, a BC like the Zeagle Tech Pac gives the lie to such fears
I have noticed how often divers disparage new ideas. I remember getting my first horse-collar ABLJ. "They're dangerous!" I was told by those who claimed to know.
And it seems like only yesterday I was being warned that BCs, then recently introduced, weren't safe because they would be inclined to float an unconscious diver face-down.
In 1993, in the company of some expert divers, I tried a wing-style BC for the first time. It was a Zeagle. We started out with a single aluminium cylinder and, yes, we found that the BC would float an unconscious diver on his face. After exhaustive tests in shallow water to prove this point, we went diving for a week, and some of the diving was very adventurous.
Within a day we were squabbling over who would be using the Zeagle. None of us intended to become unconscious divers. We simply appreciated the superior buoyancy control the wing offered over conventional BCs, and no one had any trouble keeping upright while waiting for the boat at the surface. We each accommodated, by the positioning of our weights, the different in-water trim the Zeagle offered.
Some say that if a diver drops his weightbelt he will have trouble with a wing. How often do divers drop their weights? Looking at accident reports it seems that even those who die are disinclined to do so. It's not an automatic response, so it's rarely done, even in the most dire circumstances. A rescuer might drop a casualty's weightbelt, but a rescuer is hardly likely to allow a casualty to turn face-down.
If this were an issue, we would all still be using horse-collar ABLJs. Some are. They are still the only buoyancy device to guarantee a face-up attitude.
So when I took a Zeagle Tech Pac wing for a week's leisure diving, it was like meeting an old friend. I used it in combination with twin 12 litre aluminium cylinders and the inordinate amount of lead needed to keep them under the water once almost empty.
I found the Zeagle perfectly behaved on the surface, allowing me to swim on my back with a big comfortable cushion fully inflated behind me. When waiting at the surface I didn't have to give it a second thought: I was high out of the water.
The harness, loaded with six small and six large stainless-steel D-rings, was easy to get on and unobtrusive once I was wearing it.
It has a small sternum strap with fastex buckle and a waist strap fitted with a conventional weightbelt-style, stainless-steel buckle. I suppose it might be possible to confuse this with your weightbelt, which you could inadvertently drop when getting out of the BC in the water. Then again, you should always get rid of your weights first.
In the Tech Pac version, this wing doesn't have pockets or an integrated weight system, so it's a Zeagle stripped for action. It has fittings for an optional crotch strap but I never used it, nor encountered the problem of the twin cylinders falling over my head when I ducked down.
Because I was engaged in an exercise comparing regulators, I was hung with more high-pressure hoses and second-stages than is normal, but all of them clipped away nicely.
The Zeagle has the great ability to cam-band a single cylinder or twins at will. It's just a question of threading the appropriate bands through the webbing slots at its rear.
The dump incorporated with the corrugated hose of the power inflator is positioned exactly right, although this is the only dump available to a normally swimming diver. There is a bottom dump to be used in case of inversion.
Maximum lift is massive, and there is only a small tendency to flap when the BC is used with a single cylinder - none at all with twins. This is thanks to straps that keep the bottom parts of the buoyancy bag attached to the soft backpack.
The Zeagle Tech Pac costs £320 and comes in S, M, L and XL. In size M it claims a maximum lift of 29.5kg.
Bowstone Diving Products 0161 442 0272
Unmasking the Bandit
Zorro, the Lone Ranger, Batman, Spiderman - if you want to look like a modern-day superhero when you go diving, get yourself a Dacor Bandit extra-low-volume diving mask.
Its swimming-goggle-style eye-pieces are incorporated into a black silicone skirt with the essential nose-piece for mask-clearing.
From my days as an instructor, I know that most people find mask-clearing the toughest obstacle to getting certified. For those afraid of having a flooded mask that's impossible to clear, the Bandit reduces this worry to the level of someone in a bathroom with a couple of Optrex eye-cups to empty.
I repeatedly flooded a Bandit and found that the slightest snort was enough to blast all the water from it. With the flat plate of the plastic eye cups (I can hardly call them lenses!) so close to my eyes, my vision seemed limited by nothing more than the refraction of light. This happens when light passes from a dense medium (the water) to a less dense medium (the air trapped immediately in front of the eyes).
However, the Bandit turned out to be something that everyone wanted to try but few seemed to like. I offered it around the dive guides of Dive Africa in Sharm el Sheikh, but found that no one who started a dive wearing the Bandit finished it without resorting back to their regular mask.
It's all about what you're used to. An inexperienced diver tried it and told me it gave him wider vision than his normal mask, whereas an experienced girl instructor said it made her feel dizzy. That is because the normal field of view is surrounded by a much wider field that is blurred through the plastic. Added to that is a certain amount of internal reflection (upside-down) that can be disturbing.
One dive guide - who took the Bandit from another guide in exchange for his own midway through a dive - found himself in danger of losing his escorted group because they no longer recognised him. Zorro and the Lone Ranger must have known something about disguise after all!
I enjoyed the Bandit and, although my own mask has +2 dioptre correction lenses, I found I could read my computer with the uncorrected Bandit. I'm not sure if this was an optical effect or a psychological one.
However, I still kept switching back to my regular mask if I had it with me. It seems that the Bandit's success will depend on both fashion and personal taste.
Without a cape to add to my diving equipment I felt a bit of a fraud, an only partially equipped superhero. Certain passengers on the boat even suggested that I looked less like Antonio Banderas and more like Tigger's Masked Avenger from Winnie the Pooh.
The Dacor Bandit costs £43.
Hydrotech 01455 274106
How to change a bulb underwater
When you have a winning product, others are going to try to emulate it. Underwater Kinetics, for example, had a best-seller in the form of the UK400 rechargeable diver's lantern. It was the right sort of size, balanced well in the hand under water, and had about the right price-tag. So it was no surprise that other manufacturers duly came up with products that were broadly similar.
Now, however, Underwater Kinetics is again taking a lead, though without departing greatly from the original UK400 concept. The result is the UK D4R High Pressure Xenon, a rechargeable lamp that has approximately the same dimensions as the UK400, and is not dissimilar in appearance.
The main thing that Underwater Kinetics has added is a twin-bulb assembly - and a switch that moves the chosen bulb into the central position in the reflector.
The user gets a choice of two lamp powers: 18W for brightness or 5.8W for a longer burn-time (3 hours rather than 1.25). For me, however, the big attraction is not the choice of brightnesses but the opportunity to change a bulb without leaving the water should one fail during a dive .
In fact I found little to choose between the two brightnesses, and I stuck with the longer burn-time of the 5.8W bulb and kept the brighter bulb in reserve.
In a direct comparison between the old and new designs, I found that, under water, the new UK D4R gives a wide and even beam that isn't nearly as bright as the tight hot-spot produced by its predecessor. Whether or not that is really an improvement is a question of personal preference. I quite liked the cosy glow produced by the new model.
If brightness is important to you, there is the option of the D8R High Pressure Xenon rechargeable lamp, the big brother of the D4R. This replaces the UK800 and offers roughly twice as much wattage (30W and 14W) as its smaller stablemate, with burn-times of 1.5 and 3 hours respectively.
One complaint I have is that fitting the handle to the lamp calls for a lot of dexterity and a long-shafted, fine-ended, slotted screwdriver. Luckily Bosch includes the latter with its jig-saw (for the purpose of changing blades), which I happen to own. Underwater Kinetics should perhaps take a leaf out of Bosch's book.
Twin bulbs apart, these lamps have many features in common with older UK lamps and products from several other suppliers. Accessing the battery involves unscrewing the front shroud with its rubbery protection and removing the reflector unit. The whole thing bears down on to a single O-ring once it is screwed back together.
The D4R High Pressure Xenon lamp costs £115. The D8R High Pressure Xenon costs £169. Both include mains chargers.
Sea & Sea 01803 663012
No ruby, but the price is right
Some think the Mares Ruby regulator is the best you can buy - but it is expensive. So Mares has come up with a less extravagant alternative, the VX16scs Titan with Orbiter second stage. I have no idea why products like this should require such complicated titles, especially when a similarly named regulator first stage is already available from another manufacturer - you must ask the Italians.
Like the Ruby, the VX16 has a balanced diaphragm first stage, but its high-pressure seat is of titanium instead of a gemstone. In common with most Mares regulators, this one features Dynamic Flow Control, the company's design solution to the problem of getting the air out with as few restrictions as possible.
It is a fixed unit with four medium- and two high-pressure ports, and is encased in a black rubberised paint-like material that gives it a very smart appearance.
The ports don't seem to be positioned as closely together as I remember with the similar MR16, although there will still be a problem when the regulator is used with an air-integrated computer transmitter unit in one hp port.
The machining of the A-clamp revealed an Italian flair when it came to design, and the soft rubber and plastic combination knob was a pleasure to handle with water-softened hands after a long dive.
Also like the Ruby, the VX16 has a vortex-assisted second stage that neatly dispenses with any additional knobs for venturi +/- or breathing resistance adjustment.
It doesn't have quite the retro-look appeal of the Ruby but, with a mesh front that acts as a heat sink and aids inhalation, it promises to be a trouble-free performer under wer.
Despite its all-metal look, the second stage was lightweight in the mouth. I found it gave me plenty of air, albeit in a narrow cone, but I thought that in comparison to the Poseidon and Dacor it was a little "squeaky" in the way it delivered it.
Also, the mouthpiece was a little on the small side and felt like it could be easily ripped from my mouth by a careless diver in a confined space.
Otherwise, this is the sort of regulator anyone can get on with quickly. What more can you ask for?
The Mares VX16scs Titan/Orbiter costs £328.
Blandford Sub Aqua 01923 801572
Too much information?
Cochran computers have a reputation for being fearsomely complex. They represent an engineer's approach to hardware design that doesn't always take into account just how simple some of us divers are.
I remember how hard it was for me to digest the contents of the manual for the Nemesis Nitrox II computer, and must admit I felt a headache coming on when I encountered the same problem with the new Cochran AquaNOX, which uses a similar-sized wrist unit.
I found the solution in typical diver's manner, by strapping the unit on my arm and going diving with it. The instruction book, I'm afraid, I saw as something of a last resort. "Ah," I hear my harsher critics saying, "that's typical - John B taking stupid risks yet again!"
I hasten to add that I also had a well-understood Suunto and what is if anything an even simpler-to-read Reef Marine computer strapped alongside it for safety. Self-preservation really is dear to my heart!
The AquaNOX is one of those new breeds of computer that adapts its algorithm to take into consideration such things as water temperature, ascent rate, user conservatism, water salinity, altitude acclimatisation and previous dive profiles. It can also be set for metric or imperial mode.
I found its display very readable, with maximum depth, depth, bottom time, remaining no-decompression stop diving time, ascent rate indicator, and water temperature clearly shown.
Set for air (nitrox 21) the Cochran appeared less cautious than the Suunto or Ocean Reef.I was using it, as I'm sure most divers will, at its factory-supplied settings for ascent rate, although this and the PPO2 alarm (0.5 to 1.6 bar) can be adjusted before diving by the user, with the aid of the Cochran Analyst PC interface and a suitable home computer.
Set at 18m/min, the ascent rate bar graph builds up by 3m/min segments. However, there was a time when the Suunto indicated a total ascent time of eight minutes when the Cochran indicated that a no-stop ascent of less than two minutes was sufficient.
Field programming of the AquaNOX is achieved by shorting out the wet-finger contacts using a piece of metal such as a coin. In this way, you can set oxygen percentages from 21 to 50 in one-tenths of 1 per cent increments; a depth alarm up to 99m; up to 50 per cent added conservatism; and the fibre-optic illumination on or off.
Back home, the computer buff can set to work permanently programming in all manner of personal aspects, user-configurable items and preferences.
I'll spare you the risk of headaches of your own by not going into all the details here. Suffice it to say the Cochran AquaNOX uses a 12-tissue compartment, modified Haldanian algorithm with a computation period of once per second. It can track CNS and OTU for nitrox users, and the wrist strap is long enough for use with a bulky drysuit. You can change the alkaline N-cell battery yourself when the time comes.
I followed what the Cochran AquaNOX told me while diving, understood its pre-dive planning mode, and was able to retrieve the information about the dives I had logged afterwards. If this is the sort of technology you want, go for it.
The Cochran AquaNOX costs £368.
UWI Circle 01420 544422
Appeared in DIVER - February 1999
