THE AQUA LUNG LEGEND LX SUPREME did very well with the panel of underwater judges in our comparison tests of top-end regulators that we published three years ago. However, I have never taken one for an extended diving trip, so I decided to put matters right. As someone has rightly pointed out on the www.divernet. com forums, among top-performing regulators we often struggle to find differences in performance. They all work, in fact they all work very well, and the differences in breathing characteristics can in some cases be subtle. This was not always the case, and I hasten to point out that if it were not for hard-hitting reports in magazines like DIVER, some regulators might still be as indifferent as they were 12 or more years ago, when we started doing this. It's not so much a question of the amount of air as how it 'feels'. That is something a machine can never quantify, but we humans can express our feelings about it. The Legend LX Supreme purports to be the best Aqua Lung can do when it comes to breathing performance in coldwater conditions. I really didn't expect it to be anything less than sublime. Like most top-of-the-line regulators, the first stage has four medium-pressure and two high-pressure ports. Alas, when I tried to fit the transmitter for my integrated computer, I found that there was no space for the other hoses on that side, because the ports are positioned too close together to allow for that. The diaphragm-type first stage is nice-looking, finished in all-black with some parts encapsulated in a soft black rubber coating. It is environmentally sealed to prevent cold or dirty water coming into contact with the works, and it has a few metal fins to act as a heat-sink and reduce the chances of ice-creep on the outside. The second stage has a finned metal heat-sink surrounding the hose where it meets its main body. The titanium metal ring that retains the soft front that allows easy access to the purge control also helps in this department, and it too is trimmed with soft black rubber. The venturi plus/minus (dive/pre-dive) switch is easily operated with a gloved hand, and there is a big side knob for turning up the cracking pressure needed to pull open the flow of air on each inhalation. As usual, I left this at the lightest setting, and settled for breathing less heavily if I needed less air. It's a compact second stage but the exhaust T was just big enough to route exhaled bubbles away from my field of vision. This regulator comes with a choice of mouthpieces. One is of the Comfobite style that hooks onto your front teeth, while the other is the conventional type gripped by your back molars. I was using it on an extended trip consisting of 60 consecutive dives, so I swapped one mouthpiece for the other halfway through. A change is as good as a rest. A novel addition is a rubber guard that fits over the mouthpiece and gives your lips some protection from the initial shock of entering cold water. I found an alternative use for this. When diving in water infested with man-eating plankton, I used it to protect my lips from the irritating stings around the mouth that my fellow-divers suffered. An uncomfortable side-effect resulted from the fact that I'm lucky enough to have a gap between my top front teeth (my wife says it's lucky!). The guard caused my top lip to be pressed on this gap, embossing it by drawing it through the gap, and this became a little irritating. I rang the changes between mouthpieces and guard, and all was well. As expected, the Legend LX Supreme breathed sublimely during normal diving. What I did discover, however, was that when using my camera to take portrait- rather than landscape-shaped pictures, I tended to turn my head on one side, positioning the hose end of the regulator downwards. This gave me a very wet air supply. Obviously the exhaust port let too much water back in when I exhaled at this angle. It is not something you would discover unless using a big camera turned through 90?, and looking through the eyepiece with your right eye, but it spoiled an otherwise good experience. The Aqua Lung Legend LX Supreme costs£379.