Scuba Diving Photos
ScubaLab: Reg Review
PERFORMANCE Apeks’ XTX reg line has been around for almost a decade and includes six different breathing systems. This year the entire line received some upgrades, which prompted us to retest two models to see if anything had changed in the performance department.
Turns out, not so much. The XTX200 — the top dog in the line — is still able to ace breathing-machine tests without breaking a sweat, and in the ocean, it breathes like a dream. For this year, engineers improved the reg’s gas flow and balancing properties (not that it needed it), and added a fifth port to the first stage to increase hose-routing options. The second stage continues to come with a ComfoBite mouthpiece and a choice of exhaust tees. The wider tee does the best job of keeping bubble interference to a minimum, but the narrower tee is lighter and more compact. The reg offers an efficient purge and great user adjustments.
BOTTOM LINE A smooth, dry breather in all swimming positions, the XTX200 is, as one test diver put it, a “kick-ass reg.”
The regulator review is the high point of ScubaLab’s annual gear-test program because it’s when we get to peel back the performance layers on what is arguably the most important piece of equipment in a diver’s bag. Clinical testing took place at Dive Lab, which operates the only nonaffiliated ANSTI breathing machine in the country. Then came the ergonomic trials with a test team in the Gulf of Mexico at a site called Airplane Barge off Clearwater, Florida. The reviews presented here are a cumulative summary.
HOW WE TEST: REGULATORS
Breathing Machine Tests:
>>All regs are tested as received from manufacturers.
>>Regs with user adjustments are adjusted for testing at the no-leak/free-flow point. Regs are tested on the breathing machine in a face-forward position, per industry-testing norms. (Note: Regs breathe better in a facedown position, more typical for a recreational diver.)
>>Following a surface check, each reg is tested at three different breathing rates, known as RMVs (Respiratory Minute Volumes, basically the amount of gas that can be ventilated through the lungs in one minute), at three depths, for a total of four RMV/depth combinations. These breathing rates were chosen to enable us to:
- simulate a recreational diver’s breathing rate.
- conform to recognized industry testing parameters for purposes of comparison.
- surpass normal breathing rates to determine reserve capacity (the ability to continue to deliver gas smoothly and easily, even at extreme depths and breathing rates).
>>Simulator tests are not intended to pass or fail regulators, but rather to scientifically gauge their performance based on controlled conditions.
Ergonomic Tests Explained:
ScubaLab staff evaluates each regulator in the water in 13 basic areas. Performance is tracked by numeric scores (1 to 5 – 1 being Poor, 5 being Excellent) and written comments, recorded at depth, while regs are actually being used.
Ergo Test Categories:
- Ease of breathing, swimming position: How well does the regulator deliver air when moving forward in a standard swimming position?
- Ease of breathing, face-up position: How well does the regulator deliver air when you are at depth and looking up toward the surface?
- Ease of breathing, heads-down position: How well does the regulator deliver air when you are at depth and in an inverted position?
- Wetness, swimming position: How dry does the reg breathe?
- Wetness, heads-down position: When in heads-down and face-up, how dry does the reg breathe?
- Bubble interference, swimming position: Taking into account all regulators have bubble interference to a certain degree, when moving through the water, how well does the reg deflect bubbles from your field of view?
- Bubble interference, stationary position: Taking into account all regs have interference to a certain degree, how well does it deflect bubbles from field of view when stationary?
- Ease of clearing, exhalation method: How much force is required to clear the regulator by exhaling?
- Ease of clearing, using purge button: How difficult is it to find and use the purge? How forceful is it?
- Purge-button flexibility: How stiff or pliable is the purge button/cover, and how efficiently does it clear?
- Comfort of mouthpiece: How comfortable is the mouthpiece?
- Venturi lever adjustment: Is the Venturi lever easy to find and use?
- Breating adjustment knob: Is the adjustment knob easy to find and use? Does it do its job in a reasonable manner?