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IMAGINE FLOATING IN A SWIMMING POOL in a pink inflatable armchair, martini to hand and stockbroker on the phone.
That was the fantasy view of rich people that was portrayed in comedy films of the 1980s. Now imagine floating in the ocean, with nothing to drink and your pension gone down the drain.
That's the 21st century for you.
I was musing along these lines recently, while floating at the surface after a dive in the Sudan.
I had fully inflated my Mares Morphos BC and my buddy had observed that it looked as if I was supported by something akin to an inflatable sofa.
As I had applied its direct-feed, it had just grown and grown. Had I possessed a small outboard, I might well have driven myself back to our mothership - people have made it from Cuba to Miami on less. Not only that, but the importer could supply me only with an example in size "Small', because supplies of this new BC were, at the time, so difficult to obtain.
It didn't matter. I easily strapped it about my 42in chest, and there was plenty of adjustment in the straps, even if the cummerbund could have been a little longer.
Of course, there are many BCs, mainly wings, with enormous buoyancy bags. When not inflated and under water they may have a tendency to flap and wrap around the tank, reminding me of Ellen MacArthur under full sail.
Without a fair wind, too much sail can slow you down. The Morphos does not slow you down. It is sleek and aquadynamic. In fact, it doesn't even slow you down when it comes to travelling to the dive-site, because it conveniently turns itself inside-out, zips up into itself, and becomes a useful cushion.
The Morphos must represent the ultimate single-tank BC that Mares has come up with to date. It features the pneumatic Airtrim system that originated from the HUB and the Mares-patented optional integrated-weight system which retains the weight-pockets using a positive stud system.
As a product, it is surpassed only by the more expensive Morphos Twin, which has two pneumatically operated dumps and uses stronger material in its construction. I was continually impressed by this BC during a week's liveaboard trip.
At first I was concerned that the integrated-weight pouches looked rather small, yet I was able to stow 4kg on either side. With an aluminium tank I would have made use of the rear trim-weight pockets to add a further 2kg each side, and that is surely enough for most wetsuit divers. The steel tank supplied on the liveaboard did not require the trim-weights.
The main weight-pouches slot in easily and are held in place until you want to relinquish them. I had no trouble passing them up to the RIB driver after a dive.
There is no traditional corrugated hose. The Mares Airtrim system uses pneumatic controls to operate the centrally mounted dump valve at the centre top of the buoyancy bag, via a big button near the front left of the BC.
A second big button operates the inflation valve fed with air by the direct-feed hose from the regulator. This control is large and easy to find but sleekly merges with the diver's profile.
I found I could use it easily with either hand, although it is clearly designed for use with the left.
When it came to dumping air during the ascent, I found that the Airtrim system worked smoothly and progressively. Contrary to the predictions of some obviously uninformed critics, it did not dump all my air in one go.
My only observation is that this hi-tech pneumatic system is probably very hard to deal with out at sea if it develops a fault, unlike the low-tech alternative of the corrugated hose.
I hate to see divers with the "danglies", me included. With my octopus rig on its long hose stowed under bungees around my tank, and my high-pressure hose tucked away under my waist band, the sleek Morphos presented nothing to catch or snag. That's the way it should be.
The aesthetics were spoiled only by the bit of extraneous material provided to allow the user to turn the jacket in on itself and zip it up into a cushion-like parcel. For transport, I found it more practical to spread the Morphos flat in my dive-bag. If I owned a Morphos I would dispense with this facility and slice it off.
Getting into it three or more times a day, on a heaving deck, and then transferring, fully kitted, to the RIB for a high-speed chase across the waves to the dive site was never a challenge.
The hard backpack was separated from my body by a comfortable cushion, and the shoulder harness instantly adjusted and pulled tight. The sternum strap stopped the shoulder straps from slipping off even though this BC was not supplied in my size.
Under water, the buoyancy was always where I wanted it and there was no "heavily loaded saddle-bag effect" from the integrated weights. I was always snug and comfortable .
The pockets were not enormous but certainly big enough for a current-claw and a dead fish to be used as a shark lure on one side. The left side contains the manual inflation kit for use should you arrive at the surface with an empty tank. I opted to keep this clear of other paraphernalia.
For wetsuit diving, this has to be one of the best BCs I have used in a long time. Yes, I liked it!
The Mares Morphos comes in sizes S, M, L and XL and costs £383.
Blandford Sub-Aqua 01923 801572, www.mares.com
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+ Good weights arrangement
+ Pneumatic controls
+ No "danglies"
+ Well-distributed buoyancy
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- Zip-up cushion effect not needed
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Sleek front layout, with nothing to snag.
Lower dump valve
The centrally mounted rear dump valve
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The first drysuit I tested for this magazine was tailor-made for me by Northern Diver. It had neoprene seals and, although the suit was beautifully made and fitted me perfectly, I mentioned in my report that, like all suits with neoprene seals, it was slightly damp rather than perfectly dry. The headline writer did the rest: John Bantin Tests a Dampsuit.
So Northern Diver had good reason to hate me. But then, most drysuit manufacturers hate me. Yes, it's true. It's because so few of them make a drysuit that keeps the water out when I use it.
Why? Because I tend to go under water to perform some sort of task rather than merely to swim about. Tasks usually mean using one's hands. When I grip something, the sinews in my wrists stand out. When that happens, the water often gets past the wrist-seals, especially those popular parallel latex wrist-seals fitted by many drysuit manufacturers.
Other people suffer from neck-seal rash. Yes, you must have seen it. If they wear a drysuit for long they end up looking as if someone tried to cut their throats with a blunt hacksaw.
Apollo Bio Seals promise to solve both these problems. They make an interface between the latex drysuit seal and the skin. They are made of a very stretchy, slippery, lubricated, rubbery, black material.
Sexy? They are softer than a sting ray's underside. And they say it was for the love of a sting ray's underside that Fletcher Christian mutinied on the Bounty!
Bio Seals are so stretchy that the one for the neck can easily pull over the head without touching the sides. They are shiny and they cling. They seem to have their own lubrication. I bet a lot of people will buy them to wear to those special parties I hear happen in places such as Milton Keynes or Telford.
I am told that the material is actually an incredibly tough gel that will stretch to the order of 1500% and is not easily damaged by fingernails.
Drysuit neck-seals offered no problem when donning my suit and wearing this devil's dog-collar, but I found it difficult getting my arm down past the wrist-seals while wearing the wrist version of Bio Seals. I had to roll the wrist-seals of the drysuit back and put the Bio Seals on afterwards.
But once in place, they work. They made a good seal to both my skin and the seal of the suit, thereby truly keeping the water out.
Apollo Bio Seals are available in one size for wrists (£25) and two sizes for necks, 28-35 and 35-40cm (£15)
W CJ Evans International, www.bluesports.co.uk
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+ Easy to get onand off
+ They improve the efficiency of drysuit seals
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- Don't leave them behind after a party!
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I have no agenda against any particular brand of equipment but I confess to disliking the manner in which air is delivered by some Poseidon regulators. It's what I call the "Captain Scott" effect. I admit that there are many divers who seem to like the wind whistling round their tonsils. Not me.
The Poseidon Xstream is little more than a year old now and I received an early model of this regulator that was specifically designed for use by deep technical divers.
I was agreeably surprised. Its delivery of air was sublime. I pointed out at the time that, although Poseidon had deep tekkies in mind, there would be a greater majority of divers who had no intention of going anywhere near the 200m depth for which the Xstream Deep is certified but would like to own and use such a superior item of kit. To my surprise, I had become a Poseidon aficionado.
Then Poseidon went and spoiled everything. For our top-of-the-range regulator test we were sent another example of the Xstream and our four testers each said it was horrible. I tried it and I had to agree. It was another tonsil-blaster in the old style.
So what had gone wrong? I can only think that in their rush to get a good result from our ANSTI machine, the fellows at Poseidon had tweaked that valve, but had forgotten that we were also going to have real people on the end of it.
Well, looking back at my original test, I was right about one thing. There are just not enough deep-diving tekkies in the world to make a product specifically aimed at them financially viable. Mixed-gas diving is done by a very small minority in what is a small minority interest in itself (scuba-diving, that is).
So diving-equipment manufacturers which want to stay in business are forced to look at the wider market. Hence we now have the Poseidon Xstream Dive, aimed at the discerning, air-breathing leisure-diver.
Unused and plugged ports are seen as a potential failure point by purists with multiple tanks, but if you are diving with only one first stage you will need the five medium-pressure and two high-pressure ports supplied with the Xstream Dive.
You will want an octopus second stage to sit alongside the one you are using. You will want a direct-feed to your BC, and possibly one to your drysuit too. You will want a take-off for a pressure-gauge and possibly one for the transmitter-unit of your air-integrated computer. I was pleased to find that there was space to fit this without the other hoses getting in the way.
The Xstream is an upstream servo-assisted regulator. This means that the hose must incorporate a pressure-relief valve just in case it is subjected to full tank-pressure, and the servo valve has to take up the pressure when you first turn the tank on.
This is why it is best to put your hand over the mouthpieces of the second stages to avoid them going into a dramatic free-flow.
The loud sound of the rush of air escaping when turning on the tank each time resulted in many startled faces among the other divers in the boat. But once I had overcome this trauma and mastered the technique in such a way that the entire contents of the tank were not lost, all became well and I was able to return their frightened looks with a smug gaze.
The Xstream first stage has a great coldwater design with a massive heat-sink in the form of an exposed spring that will put heat from the water presumably at a temperature above freezing and a lot warmer than the air from the tank.
The mechanism is a balanced-diaphragm rolling ball-valve and uses fewer O-rings than most other regulator designs.
Its second stage is one that can be used either way up, with the hose coming from the left or right. It exhausts exhaled air out to one side, well away from the face, avoiding the Jacuzzi-effect that is becoming so common on regulators with small exhaust-tees.
Under water, I found that it was very light in the mouth and breathed as brilliantly as the original Xstream I had tried a year before. In fact, it gave me a broad flood of air at any leisure-diving depth to which I cared take it and, I even dare to say, this Xstream was extremely subtle in its delivery. Delightful!
I now assume that some technician set that Xstream Deep to perform savagely for our earlier comparison, when what we want is a tame performance that leaves the diver feeling he has the whip-hand when it comes to inhaling.
The Poseidon Xstream Dive is not cheap. With octopus (and no other brand second stage will do, because of the higher than normal interstage pressure) it costs £653.
Poseidon 01420 84300, www.poseidon.se
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+ Can be absolutely brilliant
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- Rather expensive
- Needs to be set up correctly
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Worldwide nowadays, it is not uncommon to be able to enjoy the benefit of nitrox supplied via a membrane system. This takes out nitrogen rather than adding oxygen. It is much safer and much more consistent than partial-pressure blending and, by and large, ordinary tanks and valves can be used.
Staff of dive centres and liveaboard dive boats with membrane systems installed can simply pull off nitrox supplies at a consistent 29.9% O2 - or 31.9%, or 35.9% or whatever they will.
But of course, the divers who use these tank fills still have to check what they have been given and sign for it.
I was recently on a liveaboard so equipped, and religiously calibrated the analyser supplied and analysed the contents of each tank I used, recording it in the book provided. I was getting 29.9% every time.
However, when I looked at what others were recording for their received nitrox, the figures varied from 28% to 32%.
I commented to one of my co-divers about this curious state of affairs. He happened to be a gas-analyser engineer from Siemens and I was interested when he told me that, in view of the method by which the nitrox was being generated, the only thing he felt he needed to check was that he had not been given a tank of air by mistake.
Seeing my raised eyebrows, he went on to say that the O2 analyser provided for us by the boat operator could in no way be considered accurate.
It was one of those jobs that has a hemisphere with a small hole over the sensor. You crack open your tank valve a little and hold the hemisphere up against its orifice, reading off the figure display once it is seen to be constant.
He told me that gas analysis by an oxygen sensor depended on pressure, and in no way could the pressure of the gas controlled as we were doing it be either consistent or accurate.
All this reminded me that some years ago I had been well-impressed by a little analyser called the Alpha-1.
You connected this unit to the direct-feed hose of your BC and made use of the flow-control characteristics of the first stage of your regulator.
I got on to Alpha-1 Control Solutions, the manufacturer, and found that although it thought that this was the ideal way to do the job, it had not proved popular with divers and it had been forced to rethink. Now it supplies the unit with a hose and a connection that you can fit directly over the tank valve, whether it be DIN or for international A-clamp regulators.
A small flow-rate control valve or flow-meter is included in the hose to keep the gas supply and pressure constant over the face of the oxygen sensor cell.
This means that there are no pressure problems to invalidate a reading.
You should of course calibrate using absolutely fresh dry air rather than the air found in a building in which people are breathing, or on the aft deck of a boat in the lee of the wind and surrounded by other fumes.
Real fresh air can be relied on to contain 20.9% oxygen. Some people think it clever to calibrate with 100% oxygen. Alas you rarely can get that percentage supplied, as the cylinder in which it is stored has usually contained some air before it is first filled. So 99% oxygen is probably the best you can get in this case (closed-circuit rebreather users take note).
So why do you need to calibrate at all? Because atmospheric pressure makes a difference, the sensor ages and loses its sensitivity, and ambient temperature variations together with the temperature of the gas sampled can make a difference.
In the case of partial-pressure blending, which is still common in this country, it takes time for the gases (oxygen and air) to mix.
If you leave a filled tank overnight, you will find that the oxygen percentage has dropped when compared to a reading taken immediately after a cylinder was filled.
The Alpha-1 has an air-tight screw cap which fits over the oxygen sensor orifice when the unit is not in use. This stops the sensor working when you don't want it to, and in this way prolongs its life.
The method of sampling takes care of gas-flow inconsistencies. You just need to wait a while before analysing a freshly filled tank, to get a very accurate reading of its contents.
When you do, you can expect it to be accurate to within around 0.1%. The design has taken care of all the criteria for accurate oxygen analysis.
Not only that, but the Alpha-1 is a robust waterproof unit ideally suited to the rough and tumble and poor treatment normally handed out by divers in the harsh environment associated with boats.
The Alpha-1 Oxygen Analyser costs around £250.
Sub-Aqua Products 02380 612144, www.subaqua-products.co.uk
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+ An accurate O2 analysis every time
+ Screw cap prolongs life
+ Robustly built and waterproof
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- Not every diver will want one
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