Founded in the late Sixties by David Parker, AP Valves is a British success story. The company's first product was the auto mouthpiece. This was designed to permit an out-of-air diver to draw air from his BCD automatically using the small air cylinder commonly fitted to the jackets of that era as the emergency supply. In 1978 AP launched the 'Buddy' front-mounted BCD into a market dominated by the French Fenzy. This was its first and only single-bag jacket. Though it made some inroads, the turning point came in the Eighties as divers turned away from front-mounted BCDs towards stabiliser jackets. AP provided jackets that combined the benefits of the emerging, mostly US-driven stab jacket, with the traditional features beloved of British divers - mini air cylinders and, of course, the auto mouthpiece. Imported jackets rarely offered these features, which were of limited appeal in their home countries. AP's product line, tuned as it was to the unique demands of the Brits, found a willing market and fast became the best-selling BC range in the UK.

The Profile has been around since 1991. AP has made minor modifications to the jacket over time, with a 'bum dump', improved pockets and, this year, the addition of a dump valve incorporated into the oral inflator hose plus two stainless steel D-rings on the front.

Our testing was split between members of our Coral Queen Red Sea Test Team and the Gibraltar Sub Aqua Club, with one Profile even making it to Sipadan in Malaysia. This gave us our most widespread test base to date, because it allowed us to incorporate the opinions of divers with three or more years' experience of using the Profile with our normal 25-dive test programme results.

The Profile is an advanced design vest, meaning that it breaks at the shoulders. It has an inner urethane bag and an outer bag of 1,100-denier nylon. This is probably the heaviest weave of any recreational jacket. It has been standard construction on Buddys for more than a decade. Two unusual features are the mini air cylinder and automatic mouthpiece, of which more later (see over page).

Assembly

The Profile is straightforward to assemble. A single 50mm nylon cam band secures the jacket to your cylinder. If you ever make the mistake of unthreading it completely, a route guide is printed on the strap to aid refastening. There is a non-slip pad and a substantial centre buckle, together with a loop to keep excess strap tidied away. Our testers awarded it 90 per cent for assembly.

Comfort

The Profile uses a blow-moulded, hard back-pack that can accept twin cylinders using a simple but effective optional twinning kit. A top handle is built in. AP Valves offer a soft comfort pad as an accessory, which we did not use. A 50mm waist strap passes through this and holds the pack securely against the diver's body. A chest strap and the two fully adjustable shoulder straps are sewn directly to the outer bag.

Stand/Walk Test

Because divers often have to stand around at the dive site or walk to and from the water, we include a five-minute stand test and a 100m walk to assess BCD comfort out of the water when the equipment is obviously at its heaviest.

Our two test team divers from the Red Sea expedition aboard the Coral Queen didn't really need to walk anywhere with their Profiles. They used single 11-litre cylinders. They did complete the stand test and, instead of the walk test, evaluated the jacket during rides on the RIB through an occasional chop. Our Gibraltar team use heavy alloy single tanks with ponys and always have to walk at least 100m to the water, either down steps or a soul-destroying slope. In total the Profile scored 80 per cent for comfort.

Buoyancy

The Profile is available in four sizes, from small through to XL, with rated buoyancy from 11.75kg to 18kg. Our divers used medium and large models. As with other BCDs that we have tested, the Profile, if fully inflated, does constrict slightly and so would probably not normally be fully blown up. Therefore, in practice, lift would be marginally lower than quoted.

At the surface, where a diver will often have to wait several minutes to be picked up, it is important that the diver is comfortably clear of the water. A diver out of air and without a snorkel is vulnerable to inhaling water, especially in rough conditions. So, we measure the clearance between the diver's lower lip and the water as a guide to how well supported the diver will be. The average was about 13cm/5inches with a single cylinder.

We asked our testers to score the Profile according to whether the BCD supported them adequately clear of the water and whether it held them at a comfortable attitude, without tipping them excessively forwards, backwards or sideways.The lowest score came from a diver using a pony. Perhaps he hadn't compensated for this by taking enough lead off his weightbelt.

We also need to access the Profile's buoyancy characteristics underwater. To test the BCDs for stability we put the team throught the Diamond Reef Precision Buoyancy Program. This underwater assault course is used by US government bodies and is the best benchmark we have found for testing the buoyancy skills of our volunteers and the BCDs. By having the divers manoeuvre through the diamond-shaped hoops suspended in the water, it was possible to discover any tendency for the BCD to roll or pitch them off balance. As supervisors, we could observe the divers to look for uneven weighting, or a cylinder mounted too high or low in the pack, that might unfairly mark down the BCD.

We checked for stability (the ability of the BCD to keep the diver in a prone position without tipping the diver sideways and exaggerating the natural rolling action finning causes); barrel rolls, where air migration can jerk the diver uncomfortably; head-down attitude, adopted when looking under overhangs, and a head-up hover often used on walls or while decompressing.

The jacket scored an extremely respectable 80 per cent, which indicates that the Profile performs its primary task of properly supporting a diver underwater very well indeed.