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FOR A GROUP OF PEOPLE SEEN BY OTHERS as on the adventurous side, we scuba-divers are, on the whole, a pretty conservative bunch.
Major advances in equipment which have benefited us over the years have all met with great resistance. BCs, drysuits, RIBs, computers, rebreathers and nitrox were all seen as dangerous when first mooted, only to be adopted by the masses later.
Yes, there have been some evolutionary dead-ends such as automatic buoyancy control and certain electronic underwater navigation devices, but even these have probably been less than successful only because their price outweighed any perceived advantages.
Take the original BC, the ABLJ or Adjustable Buoyancy Life-Jacket. You wore it and put air into it as you went deeper, releasing that air again on the way up. Why did those early bottom-scratchers find this to be such a problem?
How did you put the air in? You took a breath from your regulator and blew it via a hose into the ABLJ. How did you release air? You raised the hose to the highest point and trickled it out. The hose was corrugated to make it more manoeuvrable.
With drysuits you can control your buoyancy in a similar way. You put air in on the way down, via a direct-feed hose from your main air supply, and you trickle it out either by way of a cuff-dump or a constant-volume dump on the way up.
So why do we need a corrugated hose on a BC if we don't need one on a drysuit?
The fact is that makers of BCs supplied corrugated hoses only because ABLJs had them. ABLJs had them because they were included before direct-feeds were thought of.
But no manufacturer was brave enough to supply an ABLJ without a corrugated hose, even if they realised it was unnecessary. Conservative-minded divers would not have bought it, and even today most instructors teach their trainees to use their BC as if they had an early ABLJ, raising the hose to dump air. Why, when they have efficient dump valves fitted?
Welcome to the 21st century. Goodbye corrugated hose. Hello a whole range of BCs that use the same mechanisms as a drysuit. Every manufacturer seems to be doing it, and the SeaQuest Fusion is the latest of these jackets from the Aqua-Lung stable. It includes some other recent ideas, too.
It's a sleek wing under water, and a luxury armchair at the surface. To achieve this, it has a buoyancy cell based on a ligamented design that wraps around the tank, offering the sleekest profile. Air is located in the recess between diver and tank. There is no flapping spinnaker and there are no bulky side buoyancy effects while swimming.
A second strap below the single tank camband gathers up any tendency for the bag to billow, and the substantial angled backpack holds that tank securely in position.
The harness fits snugly around you with rotating buckles, so that the straps sit where it suits you. The harness has a sternum strap and there is the usual adjustable-for-length cummerbund with strap and pinch-clip over.
Four stainless-steel D-rings supply sufficient anchorage points for dangly items. Drag is reduced to the minimum by the ligaments used in the construction of the buoyancy cell, keeping everything tight. Air is added by way of a standard-looking (Apeks) low-profile drysuit-type inflation valve with a hose that feeds from your regulator neatly through the material of the BC.
Air is dumped by means of a choice of three dump valves, and the toggles for these are fed neatly through to the front.
There is only one at the top, and it's on the right shoulder for sedate feet-first descents and controlled head-up or body-horizontal ascents.
There are two dump valves at the lower back, presumably because you have to grab whatever is easiest for a fast head-down descent, or if you suddenly find yourself floating up feet-first. The toggle for the one on the left falls naturally to hand on the left, next to the inflator.
A fold-out pocket will take a small reel and the like, and you can roll it away into an integrated pouch if it's not needed. I preferred to avoid it flapping and ignored it, leaving it where it was stowed. On the opposite side is a similar pouch which contains the oral inflation tube. This is for those who have mismanaged their air-supply and arrived at the surface with insufficient air in their tank to inflate their BC otherwise. That really is mismanaging your air supply!
The integrated-weight system uses SeaQuest's patented Sure Lock buckles, which keep everything securely where it should be unless you really want to shift it. Weights are held in place in the pouches with the help of some Velcro-covered webbing.
These weight-pockets are installed on either side and are augmented by two top-loading trim-weight pockets which will take an additional 4kg of lead. They are closed by pinch-clip buckles. Trim-weights prove useful where using floaty aluminium tanks.
In size ML, the manufacturer's recommended maximum weight capacity is 13kg. That should be enough for the biggest diver in the thickest semi-dry suit.
When it came to packing the Fusion in my dive bag it seemed very heavy and bulky, although it is made of mediumweight 840 denier cloth. It approaches 5kg on its own, yet it doesn't give a massive amount of maximum lift.
In size ML, for example, the buoyancy cell is 17 litres, which is better than many BCs but not as much as I expected.
So substantial was it that strapping myself into the Fusion made me feel like an armoured bear. However, I strolled about the aft deck of a liveaboard in perfect comfort, with the load of heavy tank and weights spread evenly between my shoulders and waist.
In the water it really became part of me. I never felt that the 15 litre steel tank I was using was actually there, because it was held in place so securely by the unique backpack and camband combination. My attitude was always perfectly horizontal when I wanted it to be.
During ascents, air was dumped efficiently and without problem, including the very last drop, by the top shoulder dump or either of the lower dumps. After a week's diving, there was absolutely no ingress of water into the buoyancy cell.
The inflation valve worked as well as you would expect the same item to work on a drysuit, except that the limited possibilities for positioning it meant that it could be worked only by the left hand. This did prove inconvenient at times when I was busy with my camera.
At the surface, the whole thing expanded to hold me upright with head held high above the surface. And at all times I felt extremely comfortable.
The Fusion represents the state-of-the-art when it comes to BC design for a single tank. It comes in five sizes from S to XL and costs a whopping £499.
Aqua-Lung UK 0116 2 12 4200, www.aqualung.co.uk
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+ State-of-the-artBC for a singletank diver
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THE BUZZWORD AMONG THOSE WHO DISCUSS UNDERWATER LIGHTING may be HID, but these recent arrivals on the scene are not necessarily the be-all and end-all of the subject. HID lights are expensive to buy, are said by some to be fragile, take time to fire-up, and give a light which, although very penetrative, is not all that sympathetic to its subjects.
There is often good reason to stick with the older technology of a quartz-halogen lamp and a big battery.
The Seacsub Lighthouse is such a lamp. At nearly 2kg and 24cm long, it's big and bulky by modern standards. It comprises a heavily anodised aluminium tube with a metal handle. Its ni-mh battery-pack takes time to charge, and you have to take the lamp apart to connect it to its "intelligent charger". But for all that, it works. Ni-mh batteries have no memory, so can be charged at any time.
You get a comfortably even beam in a warm colour range that's pretty bright. The lamp has a simple rotating switch that is easy to use under water, and a positive lock to stop it coming on accidentally in your bag and burning a hole in your suit.
It's meant to give a burntime of 50 minutes or so. Alas, the example sent to me to try would not retain a charge. I don't know if this was due to a fault with the charger or with the battery-pack but it failed after only 10 minutes or so of burntime. That might have been awkward had I been using it in the dark.
While it was working, the 50W xenon lamp was certainly effective to use even in bright Bahamas sunshine, revealing sponges and corals in their natural colours.
The Seacsub Lighthouse costs £299.
Alpha Distribution 01709 515157
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+ Simple design
+ Even, bright beam
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- Heavy to transport
- Test example faulty
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MANUFACTURERS MIGHT HATE IT WHEN I WRITE about a bad experience I had with a bit of their kit, but they forget that I hate having the bad experience just as much. Some years ago, I took a bag away on a trip and, before I had got very far, the wheels fell off! The inconvenience of handling it after that was nearly as bad as the conversations I had to endure with the boss of the manufacturer, Se–or Furioso.
After some years, when the wounds had healed, the British distributor confessed that those bags had been so bad that more than half of his sold stock had been returned under guarantee, and that he had stopped selling bags since that time.
Mares has just introduced a whole range of dive bags under the name of Technomad. They bear sub-designations based on their cubic capacity in litres. The largest is the Mares Technomad 140 and the smallest are the Technomad 100 and 100 Mesh bag. The Technomad 125 and 115 come in between.
Just as you would expect from a company such as Mares, these are not just ordinary bags. Each one is loaded with innovative ideas. The distributor was so confident in the bags' ability to do and survive the job that he sent me the whole range to try.
As I explain elsewhere in this issue, I have been known to check in rather overweight at airports, such are the demands of travelling with several sets of equipment to try for these pages, but I am not an Ivana Trump.
I rejected the idea of turning up at Gatwick with a set of five matching bags and chose one, the biggest and, in some ways, the simplest Technomad, the 140.
I wanted to give it a survival-rating and test whether it would still roll after the rocks of misfortune handed out by British and Egyptian airport-handling, and two long Egyptian bus rides, had done their worst.
Now a bag might bear the brand of a well-known scuba-diving equipment manufacturer, but dismiss the idea that it was made in that company's factory. Bags come from the Far East. The Mares bag range is no exception and the materials of the Technomad 140 were given form in a bag factory in Taiwan.
Italian design is all very well, but it's the challenge of quality control over long distances that European manufacturers must face. The 140 has a rigid U-shaped base with three strong runners riveted in place. Its soft sides form a box-like shape.
The bottom section is closed off on the inside with an internal net cover that zips into place. It's big enough to take all the dive gear of most travelling divers.
The top half closes onto this. It's a soft rectangular section that also has a damp-proof zipped cover. It's capacious enough to take all your clothes, even if you need to take something for a formal occasion, too.
The two parts zip together so that only a single zip is exposed to the outside world. Both sections have a lining that can be wiped easily using a damp cloth.
One advantage of this rather simple design over its more complicated siblings is that, size for size, it has less inherent weight of its own. So you don't end up paying excess baggage charges that include the unwanted weight of the dive bag.
Once loaded, there are carrying handles fore and aft and on one side. There is also an extending handle for use with the large nylon wheels which, in the event, did not fall off. The main problem seems to be that the 140 consumes so much kit that, fully loaded with dive gear, no baggage-handler is going to be willing to lift it.
I packed nearly 40kg of stuff into it first time before I realised that I would have to take at least 10kg out and put it in another bag. Still, such capacity is great news for ping-pong ball salesmen!
Once loaded with, say, only 25kg of kit, I can still foresee a problem. If you use the side-handle, the stress of lifting the bag is taken by the internal zips. These will get ripped out from the surrounding material. It's inevitable that a baggage handler will do this, so I suggest cutting that offending side-handle off first!
Use only the end-handles and the extending handle and the reinforced top and bottom takes care of things.
How did I get on? Well, the bag survived its first trip down to Southern Egypt well, with nothing more than a bit of edge-piping scuffed. So I immediately loaded it ready for a second trip elsewhere.
The Technomad 140 costs £115.
Blandford Sub-Aqua 01923 801573, www.blandfordsubaqua.co.uk
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+ You'll never need a bigger bag
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- Too heavy to lift when fully loaded
- Get rid of that side handle
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We often take our air supplies for granted, but they rely on good compressor maintenance and regular filter changes. It's not always like that. Anyone who has had the dubious experience of an "oily fill" will know that awful feeling of gagging and retching that can accompany it.
In the days when I had my own air-station in a Mediterranean resort, I like to think we ran things impeccably, but I made the mistake of visiting another dive centre and got a bad fill after a dive with it. Even though I was able to drain down the tank and refill it with clean air as soon I discovered what I'd been given, the taste lingered on.
The owners of the other dive centre denied giving me a generous helping of oil and were, presumably, equally surprised one day when their compressor exploded in a thousand and one pieces inside their compressor room. You can compress air but you can't compress oil!
Nowadays I tend to use rented tanks. If I get a bad fill, I simply ask to swap it for a better tank and leave the owners to sort out the problem. Thank goodness most compressor-operators do the job properly. But that is not always the case and it is not always in the third world that problems arise.
The people at Apollo, in Japan, feel that the problem may be more prevalent than it probably is. They have introduced a personal breathing-filter, the Apollo Bio-Filter.
This screws in-line between the regulator first stage and the hose to the second stage. It takes the form of a nicely machined bit of aluminium that contains an activated-carbon filter at one end and a large foam pad to which one can add water at the other. The carbon filter removes taste and the water-soaked pad is there to moisturise the air that it is assumed has been properly dried in the process of compression. So, no more dry throat during a dive.
That seems like a good idea, doesn't it? But then we come to the practicality of using it, which is where this, like a lot of good ideas, falls down. The first thing that became apparent to me was that once in place, the filter formed a perfect handle by which the ill-informed might attempt to lift a fully-kitted tank.
There was also the unexpected problem of primary hoses having a different thread diameter to other low-pressure hoses, so it wouldn't fit unless I used the alternative second-stage hose.
Consider too the cost of the activated-carbon filter cartridge, which needs to be changed for every few hours of diving, and the fact that the moisture pad needs to be kept clinically clean, while the water added to it should be pure too, if you don't want to swap one problem for another. So instead of filtering out a problem after it comes out of your tank with your air, why not concentrate on seeing that the problem is not there in the first place?
If you get your tank filled regularly at the same place, I'm sure you'll be quick to tell the compressor operator of a problem. You won't want your tank contaminated, because it might well stay that way, Bio-filter in place or not.
If you're away in a strange place, refuse to use a tank with air that tastes funny, and if it starts to taste funny halfway through a dive, end the dive immediately.
A properly run compressor will not give you flavoured air and, thanks to the prevalence of nitrox installations with double-filtering, that's getting rarer. If a dry throat is a problem, I suggest you drink plenty of water prior to diving. It seemed to cure that particular problem for me.
The Apollo Bio-filter costs £95.95, replacement filters £6.
CJ Evans International 01258 451269, www.bluesports.co.uk
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+ Filters out taste and puts back moisture
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- Something you should not need
- Makes a handy but dangerous handle
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