October 2002
By John Brumm

|Related Link| |---| | Regulator Test Score Charts| Sixty-nine regulators ranging in price from $160 to $1,600, were recently collected, inspected and subjected to intensive computer-controlled breathing simulator tests at an independent test facility. From there they were handed over to a team of test divers for a series of time-proven in-water tests. In total, 690 subjective data points and over 4,800 simulator data points were compiled and crunched. Our findings are presented on these pages, the results of the largest head-to-head comparative evaluation of scuba regulators ever conducted.

As you'll see, the vast majority of regulators performed admirably, while many performed exceptionally. Clearly, regulator engineering has come a long way from the days of the double hose rig.

We found a general correlation between a regulator's price and both its breathing machine and in-water performance. Does that mean you have to spend yourself into the poor house for a decent reg? Not necessarily. The key is to match your regulator to your personal diving patterns. If you're a casual diver who never comes close to the maximum recreational diving depth, and you never plan to, then perhaps you don't want or need a high-performance regulator. Conversely, if your diving patterns are more aggressive, if you're a deep diver or a tech diver, then you'd probably be better served by a regulator loaded with reserve capacity.

After all, you don't need an SUV with four-wheel drive if you're only driving to the corner store. On the other hand, it's probably not a good idea to go off-roading in a Honda Civic.

LAB & BREATHING SIMULATOR TEST PROTOCOL

At an independent test facility, each regulator was tested on an ANSTI breathing simulator test system designed to stress regulators to extremes under controlled conditions. Following a surface check, each regulator was tested at three breathing rates at three depths each, capturing seven data points per breathing rate/depth for a total of 70 data points per regulator, or 4,830 data points in total.

Tests were performed at a supply pressure of 725 to 760 psi, lower than past Scuba Lab tests (which were done at 1,500 psi). This exerted additional stress on the regulators. If a regulator can perform well at this low supply pressure, it will invariably perform wonderfully at a higher supply pressure.

Note: Simulator tests were not intended to pass or fail regulators, but rather to scientifically gauge their performance based on controlled conditions. What's more, breathing machine performance does not necessarily reflect in-water performance, simply because there are too many real-world variables that simulators can't measure. A machine might be able to tell you how hard or easy a regulator works to deliver gas at certain depths and breathing rates, but it can't tell you about a regulator that stutters or whistles, or a purge so stiff that clearing is difficult, or whether a regulator will choke you with water when you go head-down at 50 feet.

So while breathing simulator results are important, they represent only half the story. To capture the complete picture, you need to consider both breathing machine performance and subjective in-water performance.

DEFINING SIMULATOR BREATHING RATES

Regulators were tested at three breathing rates, known as RMVs (Respiratory Minute Volumes, basically the amount of gas that can be ventilated through the lungs in one minute). These breathing rates were chosen to enable us to 1) simulate a recreational diver's breathing rate, 2) conform to recognized industry testing parameters for purposes of comparison and 3) surpass normal breathing rates to determine reserve capacity. Here are the test rates, what they represent and how you can apply them to real-world diving situations.

37.5 RMV
This breathing rate is very close to how a physically fit recreational diver might breathe taking slow deep breaths while swimming a long distance (for comparison, a relaxed diver making a drift dive or taking photographs will be breathing at about 22 RMV or less). A diver could theoretically maintain 37.5 RMV for five minutes or longer without becoming significantly winded. From an engineering standpoint, this rate also gives a good view of the smoothness or lack of smoothness of a regulator's demand valve, and it shows a consistency curve when compared to higher RMVs.

62.5 RMV
This is the standard "high work rate" used by the European conformance standard EN250 for evaluating regulator performance. It is also the U.S. Navy's primary qualifier breathing rate, although they use many work rates in their various tests. Considered to represent "heavy work," a recreational diver in excellent condition aggressively chasing a huge bat ray through open water would be able to maintain 62.5 RMV for only two or three minutes.

75 RMV
Only the U.S. Navy and now Scuba Lab use this breathing rate to identify equipment potential or limitation. This is considered an "extremely" heavy work breathing rate. A diver in excellent condition can breathe at 75 RMV for only about a minute.

Why test at this extreme rate? Beyond determining a regulator's reserve capacity in high-stress conditions, this rate can also provide a pretty good indication of whether a regulator is capable of supporting two divers at depth while buddy breathing (75 RMV divided by two equals 37.5 RMV).

IN-WATER TESTING

Regulators were evaluated on the following criteria:

• Ease of Breathing. How well does the regulator deliver air when the diver is propelling himself forward in the swimming position?

• Bubble Interference. Taking into account that all regulators have bubble interference to a certain degree, when looking down, straight ahead, up at a 45-degree angle and straight up, do the bubbles rise into the diver's field of view at an average rate, less than average or more than average?

• Wetness. During normal swimming and when in odd positions, does the regulator breathe wet or dry?

• Ease of Clearing. How difficult is it to find and use the purge? How dry is it after being cleared? How forceful is the purge? How much force is required to clear the regulator by blowing?

• Adjustments. If the regulator has diver-controlled adjustments, how easy are they to find, grip and turn? Do they do their job in a reasonable manner?

• Different Positions. With the diver in a head-down or face-up horizontal position, how is breathing affected? Is it harder or easier? Wetter or drier?

• Comfort. How comfortable is the mouthpiece? Hose length and stiffness? Buoyancy of the second stage? How does the second stage feel in the mouth?

CONSUMER ALERT! UNSAFE AT ANY DEPTH

Over the course of this comparative evaluation, two regulators failed to meet even the most minimal breathing simulator tests. They look very similar and may well be made by the same original equipment manufacturer.

One is currently being marketed as the R-8 PARAGON 2000 by Sunshine Diving of Lutz, Fla. When hooked up to the breathing simulator, this reg was able to reach a depth of only 79 feet at 37.5 RMV before exceeding established test limits. When switched to the higher breathing rate of 62.5 RMV, the reg only made it to 24 feet before exceeding limits again. To make matters worse, during in-water tests a first-stage seal failed. Luckily, it happened at a relatively shallow depth.

Scuba Lab contacted Rick Morrison at Sunshine Diving and relayed the results of the tests. He assured ScubaLab he would contact the manufacturer immediately with test results and would inform us of any further developments.

The other regulator, called the MiniPro, was formerly distributed by Cochran Undersea Technology of Richardson, Texas. When hooked up to the breathing simulator and operating at the lowest breathing rate of 37.5 RMV, this regulator was only able to reach 99 feet before exceeding established test limits. When switched to the higher breathing rate of 62.5 RMV, the reg was able to reach a depth of only 28 feet before exceeding limits again.

ScubaLab contacted Martin Heerschap at Cochran Undersea Technology with test results. He informed us that the MiniPro was no longer part of the Cochran line. However, there are still MiniPros out in circulation. In fact, ScubaLab purchased one just a few months ago from a Southern California dive shop.

Our message here: These two regulators should be considered unsafe for recreational diving. If you come across one of these regulators in a dive store, we urge you to inform the store owner of these test results and ask him to contact his distributor.

TIDBITS

• The worst regulators will often give their best performance in shallow water.

• The best regulators will often give their worst performance in shallow water.

• The easiest-breathing position for a regulator is the standard swimming position.

• The most difficult breathing position for a regulator is being vertical in the water and looking straight up at the surface, followed by face-up swimming and the inverted, heads-down position.

• In general, adjustment knobs have a minimal effect on both simulator and in-water breathing performance.

• Almost all adjustment knobs and switches are difficult to use wearing gloves.

• Most modern second stages, when measured in salt water, can alternately be slightly buoyant, slightly negative, or neutral, depending on the position of the second stage in the water, how much water is in it, etc. Bottom line: The better second stages are so light that their degree of buoyancy--or lack thereof--has become a moot point.

• What might be considered a "wet" reg might not be wet at all. Keeping the reg in your mouth right from the giant stride will tend to make for a drier-breathing dive. However, if removed from the mouth, a reg will fill with water, which is either difficult or easy to completely clear, depending on the regulator and your position in the water.

SECTION 1: REGULATORS UNDER $300 -- You Can Get a Good Regulator for a Good Price.

|||| |---|---|---| | AQUA LUNG Calypso AQUA LUNG Titan BEUCHAT VS3 GENESIS SCUBA Yukon INTERNATIONAL DIVERS Seaira Spirit Flowby IST SPORTS Proline R10 IST SPORTS Proline R20 MARES MR12 Axis MARES MR12 Proton | OCEAN REEF Enterprise 6010 OCEANIC Alpha 7 CDX OCEANIC Alpha 7 SP4 OCEANIC Explorers SP4 PARKWAY Atlas 2+ PARKWAY Nova 2 | SCUBAPRO MK2+/R190 SUNSHINE DIVING R-2 SUNSHINE DIVING R-3 SUNSHINE DIVING R-7 SUNSHINE DIVING MT9 ZEAGLE Envoy |

|Related Link| |---| | Regulators Under $300 Test Results| Testers' Choice Models

AQUA LUNG TITAN
Aqua Lung's Titan is commonly found in rental inventories, and for good reason; it's a solid performer with a reputation for reliability. Earning respectable scores in both simulator and subjective tests, the Titan is fitted with Aqua Lung's Comfo-Bite, a mouthpiece that helps secure the regulator in your mouth. In-water tests showed the Titan to be a little wet in the heads-down and face-up swimming positions.

INTERNATIONAL DIVERS SEAIRA SPIRIT FLOWBY
A solid performer at all depths, IDI's Seaira Spirit is a simple, no-nonsense regulator. It has less bubble interference than average and breathes well in the swimming position. In other positions, performance lags a bit, but not to the point of distraction. The mouthpiece is small, but female test divers seemed to prefer it over many other mouthpieces.

IST SPORTS PROLINE R10 & R20
IST Sports' brand-new R10 adjustable and R20 nonadjustable regulators dominated breathing simulator tests in this price group. The R20 not only earned a perfect score, it was able to exceed 300 feet at the maximum breathing rate while maintaining a work of breathing of only 1.0 joule per liter--an outstanding achievement for a budget regulator. In-water tests show the R20 to breathe dry in all positions. The R10, while delivering fair breathing performance in the swimming position, has a tendency to breathe wet in a heads-down or face-up position.

MARES MR12 AXIS & PROTON
Both of these regulators are smooth breathers in all positions and drier than most. Sharing the same balanced diaphragm first stage, the differences between these two regs can be found in their second stages. The Axis is a bit larger, has an easy-to-use button-style purge, and is fitted with a longer hose and conventional mouthpiece. The Proton second stage is smaller and has a stylish mesh-grid faceplate designed to reduce the likelihood of freeflow when swimming in strong currents. The hose is softer than what's on the Axis and the mouthpiece provides extended bite tabs for added comfort.

SCUBAPRO MK2+/R190
Scubapro's MK2+/R190 is a time-proven performer both on the simulator and in the water. The reg earned the highest subjective scores in this price group, earning its best marks in ease of breathing, dryness and comfort. The rather large second-stage casing is fitted with Scubapro's Safe-Grip mouthpiece, which was a favorite among test divers for comfort and security. The owner's manual for this reg is among the best, with lots of good information that applies to regulators in general.

SECTION 2: REGULATORS $300-$400 -- Midrange Models Deliver Better-Than-Average Performance.

Models reviewed:

|||| |---|---|---| | APEKS AT20 AQUA LUNG Titan LX ATOMIC AQUATICS ZI BEUCHAT VXT8 CRESSI-SUB Air Plus CRESSI-SUB Air Tech DACOR Viper | DIVE RITE RG1200 GENESIS SCUBA Atlas MARES V16 Proton OCEANIC Gamma 2 CDX OCEAN REEF Enterprise TR94 Polar OCEAN REEF 6600 Dynamic OCEANIC Gamma 2 DX4 | OCEANIC Gamma 2 PX2 SCUBAPRO MK2+/R380 SCUBAPRO MK16/R380 TUSA Platina RS130 TUSA Platina RS230 ZEAGLE DS-IV |

|Related Link| |---| | Regulators from $300 to $400 Test Results| Testers' Choice Models

APEKS AT20
Twenty-five percent lighter than its T20 predecessor, the Apeks catalog claims its smaller AT20 is easy on jaw fatigue, and in-water tests bear this out. Referred to as an "entry level" regulator, the AT20 uses a balanced second stage and offers good breathing characteristics (although there is a slight stutter on the inhale). It is also dry in all positions. The reg clears easily thanks to an efficient center-button purge. The AT20 is fitted with the Comfo-Bite mouthpiece.

AQUA LUNG TITAN LX
Earning perfect scores in the simulator tests and solid scores for in-water performance, Aqua Lung's Titan LX is a good breather in all positions with acceptable bubble interference and an efficient purge. The Venturi switch is easy to use and clearly marked.

ATOMIC AQUATICS Z1

Earning perfect simulator scores and some of the best in-water scores in this price group, Atomic's Z1 (so-named for the zirconium/nickel coating on the brass valve body of the second stage) was a favorite among test divers. With a compact first stage offering six low-pressure ports, a long supply hose and a lightweight pressure-balanced second stage, this regulator is efficient and comfortable. In the water, the Z1 offers very good breathing performance in all positions. It also breathes dry and clears easily thanks to a very powerful purge. The reg is equipped with a breathing resistance knob and "Automatic Flow Control" instead of a pre-dive/dive switch. According to Atomic, this is a depth-activated venturi control that automatically balances performance and stability (as depth increases, a vane in the second stage gradually moves out of the air path).

GENESIS SCUBA ATLAS
With strong performance on the simulator and solid in-water scores, the Atlas provides above-average air delivery in all positions, breathes dry and has an efficient purge. The mouthpiece caused minor discomfort for some test divers, although others had no problem with it. The pre-dive/ dive switch is very small and not clearly marked. The Atlas uses a unique method for keeping water out of the piston first stage. While other manufacturers use silicone or liquid, Genesis uses an air seal system called Dry Air Demand (DAD). The Atlas showed little loss of performance at increasing depths and RMVs.

OCEANIC GAMMA 2 CDX
Oceanic's Gamma 2 CDX comes with a compact first stage designed to prevent internal corrosion and contaminant build-up by protecting critical seats and O-rings from harsh environments. Combined with an updated second stage, the reg outperformed all Oceanic entries on the breathing simulator and delivered respectable performance in the water. The reg earned solid scores for breathing in the standard swimming position and remained dry in all positions.

SCUBAPRO MK2+/R380
Near-perfect simulator scores combined with above-average in-water scores for ease of breathing, dryness, clearing and comfort put the MK2+/R380 at the top of the performance pack while carrying the lowest price tag in this group. The R380 second stage is 25 percent smaller and a few ounces lighter than its R190 cousin. It's a very comfortable reg with Scubapro's "Safe-Grip" mouthpiece. While it performs well in all positions, the reg tends to be a noisy breather. The VIVA pre-dive/dive switch is clearly marked and effective in preventing surface free-flows. The reg comes with a nice-fitting dust cap and a reusable mouthpiece clamp that can easily be replaced with a standard zip-tie if it doesn't suit your purposes. Scubapro's owner's manuals have a lot of good information applicable to regulators in general.

SCUBAPRO MK16/R380
While it shares the same second stage as the MK2+/R380, Scubapro's balanced diaphragm MK16/R380 is more suited for harsh environments. The first stage features two high-flow low-pressure ports along with two conventional low-pressure ports to maximize air delivery. In the water, the MK16/R380 is lightweight and comfortable, thanks in large part to the Safe-Grip mouthpiece. The reg is a good, albeit somewhat noisy, breather. The reg dives dry and purges efficiently. The clearly marked VIVA pre-dive/dive switch is effective in preventing surface free-flows. A great dust cap and a reusable mouthpiece clamp are standard, as well as an owner's manual with lots of good information applicable to regulators in general.

SECTION 3: REGULATORS OVER $400 -- Top-Priced Regs Give You More for Your Money.

Models reviewed:

|||| |---|---|---| | APEKS ATX50 APEKS TX100 APEKS ATX200 AQUA LUNG Legend AQUA LUNG Legend LX AQUA LUNG Titan Micra ADJ ATOMIC AQUATICS B1 ATOMIC AQUATICS M1 ATOMIC AQUATICS T1x | BEUCHAT VX4 Evolution BEUCHAT VX10 BEUCHAT VXT10 Iceberg DACOR Viper America DACOR Viper Metal GENESIS SCUBA OZ-TI GENESIS SCUBA GS2000 INTERNATIONAL DIVERS Seaira Tri-Metal MARES Proton XL PARKWAY Stealth Chrome Titanium | SCUBAPRO MK16/S550 SCUBAPRO MK18UL/S600 SCUBAPRO MK25/G250 HP SCUBAPRO MK25/S550 SCUBAPRO MK25T/S600T ZEAGLE ZX-50D ZEAGLE ZX-Flathead VI |

|Related Link| |---| | Regulators Over $400 Test Results| Testers' Choice Models

AQUA LUNG LEGEND & LEGEND LX
New to the Aqua Lung line, the Legend and Legend LX use the same "over-balanced" diaphragm first stage fitted with an environmental dry kit. The two high-pressure ports and four low-pressure ports are angled for optimal hose routing. Both regs use a pneumatically balanced second stage, have relatively wide exhaust tees that cut down on bubble interference and are equipped with effective venturi switches. The LX also comes with a resistance adjustment knob and a gold titanium accent ring on the second stage. In-water tests showed both regulators to be very good breathers and dry in all positions. The flexible full-face purge is efficient, and Comfo-Bite mouthpieces keep second stages securely in the mouth. Both regs earned perfect scores in simulator tests.

ATOMIC AQUATICS M1
The M1 from Atomic Aquatics is a brand-new regulator designed with Monel internal parts. Monel is a high-grade stainless steel known for its strength, corrosion resistance and oxygen compatibility. The M1 earned perfect simulator scores and ranks near the top with its in-water performance. A real easy breather in all positions, the M1's exhaust tee is wide, resulting in far less bubble interference than average, even when stationary. The resistance knob makes it possible to control a tendency to free-flow when making head-first descents. The M1 is also equipped with Atomic's Automatic Flow Control feature which, according to the company, eliminates the need for a pre-dive/dive switch by automatically adjusting for depth.

ATOMIC AQUATICS T1x
Atomic's T1x is the T1 (with titanium first and second stages) packaged with an environmental seal kit, a titanium accent second stage kit and a padded regulator travel bag. Like the M1, the T1x aced all breathing simulator tests. The lightweight T1x is a little frisky near the surface; it will free-flow as you descend head-first with the resistance knob turned full-out. Of course, this can be dialed down. Otherwise, everything tends to smooth out by itself once you get a little depth. The T1x earned some of the highest in-water scores in breathing, dryness and clearing (thanks to a great purge), and very good overall scores in comfort.

SCUBAPRO MK16/S550
The MK16/S550 is the least expensive Scubapro model in this price group. However, thanks to its environmentally sealed balanced diaphragm first stage, it is better suited for harsh environments than some of Scubapro's other models. The MK16 first stage features two high-flow low-pressure ports and two conventional low-pressure ports to maximize air delivery. Hooked to the lightweight, pneumatically balanced S550 second stage, it produced perfect simulator scores. The MK16/S550 ranked near the top for in-water performance as well. Displaying very good breathing characteristics in all positions, it is drier than most and features an effective but slightly stiff purge. Its Sure-Grip mouthpiece continues to be rated as the most comfortable among test divers. The dual positions on its VIVA pre-dive/dive switch are clearly marked.

SCUBAPRO MK25/S550
Combining Scubapro's MK25 first stage and the pneumatically balanced S550 second stage results in an air delivery system capable of acing the breathing simulator tests. In-water subjective tests showed this first and second stage combo to be consistently dry in all positions. It also produced very good breathing in the swimming position, with slightly less performance in alternate positions when compared to other Scubapro models. The Safe-Grip mouthpiece is comfortable and contributes to a secure second stage.

SCUBAPRO MK25T/S600T
The MK25T first stage features a super-light titanium body, a forged titanium yoke and titanium internal components. This is an air-balanced flow-through piston design with a composite piston (stainless steel stem, technopolymer head). Along with the standard MK25, this is the only balanced piston first stage to have an outside intermediate-pressure adjustment (like the ones found on many diaphragm first stages). The S600T second stage is identical to the standard S600 except for a titanium trim ring on the purge cover, a titanium co-molded insert, and a gray low-pressure hose. This special combo comes with an embroidered regulator bag. The MK25T/S600T earned perfect scores on the simulator tests. It also tied with the MK18UL/S600 for the top overall subjective scores of this review. In the water, the regulator proved to be a great breather in all positions. It was also dry and produced less than average bubble interference. A powerful purge made it easy to clear, and both adjustments were effective. This was the favorite reg among test divers in this price group.

The Rest of the Story

|Related Link| |---| | Regulator Test Score Charts| Want to really know the score? Click here to view the actual breathing simulator scores for all regulators in this test group for all test depths and breathing rates, along with a breakdown by category of each regulator's in-water performance.

MANY THANKS

To Mike Ward, Lisa French and the rest of the staff at DiveLab of Panama City Beach, Fla., for their excellent work on the ANSTI breathing simulator and for their assistance in compiling data for this article.

FOR MORE INFO

AQUA LUNG (760) 597-5000; web: www.aqualung.com

ATOMIC AQUATICS (714) 375-1433; web: www.atomicaquatics.com

BEUCHAT (305) 548-3483; e-mail: beuchatdiving.com

CRESSI-SUB (800) 338-9143: web. www.cressi-sub.it

DACOR (203) 852-7079; web: www.divedacor.com

DIVE RITE (904) 752-1087; web: www.diverite.com

GENESIS SCUBA (949) 581-1300; www.genesisscuba.com

IDI (800) 257-2822; www.sip.net/idi

IST SPORTS (626) 815-9790; web: www.istsports.com

MARES (203) 855-0631; web: www.mares.com

OCEAN REEF (800) 922-1764; www.oceanreefgroup.com

OCEANIC (510) 562-0500; web: www.oceanicworldwide.com

PARKWAY SCUBA (800) 587-2822; www.parkwayscuba.com

SCUBAPRO (619) 402-1023; web: www.scubapro.com

SUNSHINE DIVING Fax (813) 909-9195; e-mail: sdei99@yahoo.com

TUSA (562) 498-3708; web: www.TUSA.com

ZEAGLE (813) 782-5568; web: www.zeagle.com