GET MORE For more information and charts on the alternate inflator regs tested in this issue, turn to In Depth, page 90, section 3. ALTERNATE INFLATOR REGULATORS THAT STREAMLINE YOUR When divers choose an alternate inflator regu- lator, it's often with the thought of streamlin- ing their gear, a laudable goal. What they may overlook is how well the combination of a BC power inflator and backup regulator performs all its critical functions when you need it most— an unplanned air-sharing situation. As a backup breather, your inflator reg's breathing performance should be a prime consideration. After all, standard practice with these units is to hand your primary reg off to the diver in need while you switch to the back- up. As with any air-sharing situation, you wil also need to abort the dive by making a safe, controlled ascent, so the second thing to con- sider is how well the inflator reg allows you to control buoyancy both in normal circumstances and when you are breathing from it. Good news: Our most recent test of alter- nate inflator regs (or octo-inflators as they are often called) shows that all of the following models can be counted on to perform at rec- reational dive depths and breathing rates. But we also found distinct differences, including two inflator regs that could handle the most extreme breathing tests we threw at them.

We invited all major manufacturers to submit their inflator regs for this review. After making sure all of the units were working properly, we headed to Panama City, Fla., and Dive Lab, an independent testing facility. We put the units on an ANSTI breathing simulator to measure their breathing resistance, or work of breathing (WOB). Each reg was subjected to a moder- ately high breathing rate (37.5 RMV) at depths of 132 feet and 165 feet. Then we cranked up the breathing rate to an extreme level (62.5 RMV), in order to see how much reserve capac- ity the regs had. To ensure an even playing field,...

FEATURES: The Gemini is a new star among alternate inflator regs thanks to a combination of* easy-breathing performance and well-designed controls. The slim, oval profile has a sizeable yellow^ deflate button anda smaller round inflate button for touch recognition. The lightweight composite housing is fitted with a standard-size mouthpiece that is replaceable. It's also nitrox-ready for mixes PERFORMANCE: According to both test divers and the ANSTI machine, this octo-inflator provided some of the best breathing performance among the regs in this review. "This is a very easy breather, as good...

ERNATE INFLATOR REGULATORS Inflator Regulators »ANSTI BREATHING SIMULATOR The ANSTI machine is the international industry standard for scientifically evaluating a regu- lator's performance. It measures a regulator's work of breathing (WOB) in joules per liter (j/l) for each complete inhale/exhale cycle. We test alternate inflator regulators at four dif- ferent RMV/depth combinations (RMV stands for Respiratory Minute Volumes, basically the amount of gas that can be ventilated through the lungs in one minute). All simulator tests are performed at a supply pressure of 725-760 psi. If a regulator...