July 2004
By John Brumm
Photography by Paul Nurnberg

Buying a regulator is a lot like buying a car. Both are big-ticket items where performance is key, but you've also got a wide range of prices, features and comfort options to sort through when deciding which one is right for you.

If you're buying a car, you can test drive as many different models as you like and consult numerous sources for objective performance data like acceleration and braking distance. Regs are a different story. It's virtually impossible for the average diver to take all the new models for a swim, and there is only one source for truly objective performance data on how well a reg delivers air in a variety of situations.

You're looking at it. Each year, ScubaLab evaluates the latest regulator models with one goal in mind--empowering you to make an informed, confident buying decision.

Putting the Lab in ScubaLab

As with all our past reg reviews, we first put these 15 new models on an ANSTI breathing simulator to measure the work of breathing. Our tests simulate everything from an easy swim at 132 feet to a panicked air-sharing situation to a hard swim at 198 feet. Thanks to the accuracy of the ANSTI machine, we gathered more than 1,000 data points on these regs and more than 150 pages of breathing loops, a graphic representation of a regulator's total inhalation and exhalation performance.

Then we assembled our team of experienced test divers and spent two days diving these regs in ocean conditions. Each diver rated each reg in six ergonomic categories ranging from the most important (like ease of breathing) to moderately important (ease of purging) to convenience items (comfort). Here we collected 800-plus ergonomic data points, along with 90 waterproof pages of test diver comments.

A User's Guide

The ratings and reviews that follow are based on the combined results of both the simulator and the ergonomic tests. We've summarized our findings here in the text and broken out all the data in the charts on pages 98 and 99. There you'll find the results from each test broken down into scores of 1 to 5. Whenever you see the words Excellent, Very Good, Good, Fair or Poor in bold, those comments correspond to specific scores in the charts: Excellent=5; Very Good=4; Good=3; Fair=2; and Poor=1.

The Reviews

Past ScubaLab reviews divided regulators into three basic price categories: Under $300, $300 to $400, and Over $400. With fewer new regs available for review this year, we adjusted the price categories to Under $500 and Over $500. Regs are presented in their respective categories in the order of their performance and 2004 Testers' Choice ratings are for the top regs within their price range.

Under $500

2004 Testers' Choices

These three budget breathers earned more simulator points, and more ergo points, than their price-class competitors, rivaling even regulators costing twice as much. All earned Very Good ratings for ease of breathing in the swimming position, dryness and clearing. Within this year's Testers' Choice grouping, the Calypso holds a slight edge over the Mares models for comfort.

|| |---| |

| | Aqua Lung Calypso| Aqua Lung Calypso

> SIMULATOR SCORES: 19 out of a possible 20.
> ERGO SCORES: 53 out of a possible 70.

Aqua Lung calls its new Calypso an entry-level regulator, but this updated version of an old favorite is so much more. This reg handled the breathing machine with a near-perfect score, then racked up the highest total ergo score in its price class. In the water, the Calypso proved to be a very dry, very easy breather. The lightweight second stage produced very little bubble interference, and earned a Very Good rating for comfort, due in part to its Comfobite mouthpiece. A pliable polyurethane cover makes it very easy to manually purge. The dive/pre-dive switch is easy to find and use, even when wearing gloves, and is marked more clearly than most.

But the good stuff doesn't stop there. The Calypso's second stage can be disassembled without tools, and the first-stage parts inventory has been streamlined to simplify servicing. In short, this is a whole lot of reg for not a lot of money. On top of a limited lifetime warranty, Aqua Lung offers a free parts replacement program to original owners.

|| |---| |

| | Mares MR12/Axis Pro| |

| | Mares R2/Axis Pro| Mares MR12/Axis Pro

> SIMULATOR SCORES: 19 out of a possible 20.
> ERGO SCORES: 50 out of a possible 70.

Mares R2/Axis Pro

> SIMULATOR SCORES: 18 out of a possible 20.
> ERGO SCORES: 50 out of a possible 70.

These two regs may be easy on the wallet, but they're anything but stingy when it comes to performance. Both turned in Very Good to Excellent work of breathing numbers on the simulator. Test divers rated them Very Good breathers in the swimming position and very dry in all positions. The simple center-button purge was rated Very Good by test divers for being easy to find and use.

The regulators share the same second stage, which is free of user controls and uses a mesh grid faceplate to minimize free-flow when swimming into strong currents. The differences between the regs lie in their first stages. The MR12 is a balanced diaphragm, the R2 an unbalanced piston. Both are equipped with Dynamic Flow Control, which is a priority low-pressure port for the primary second stage. According to Mares, this cuts down on inter-stage pressure drops during inhalation, reducing inhalation resistance. Although the regs performed virtually identically in the water, the R2 earned better comments from test divers for ease of breathing in the heads-down position. The regs we tested are not designed to be used with nitrox, but according to Mares, there are nitrox versions available.

Good Performers

These are simple workhorse regs delivering respectable simulator performance, Good in-water marks for all-position breathing, and Good to Very Good marks for dryness and bubble interference.

|| |---| |

| | Sherwood Scuba Brut| |

| | Sherwood Scuba Magnum| Sherwood Scuba Brut & Magnum

> SIMULATOR SCORES: 13 out of a possible 20.
> ERGO SCORES: 48 out of a possible 70.

The Brut and Magnum represent the economy end of Sherwood Scuba's redesigned stable of workhorse regulators. The new line is built around a keep-it-simple philosophy, using compact, oblong second stages and piston first stages sporting a unique dry air- bleed system. This patented design increases durability, says Sherwood, while stabilizing output pressure and resisting the effects of freezing. The Brut's unbalanced first stage is the most basic version of this design. The Magnum's balanced first stage offers an additional high-pressure port. Both offer primary low-pressure ports to optimize flow to the second stage.

Both regs delivered Very Good simulator scores at the breathing rate that most closely represents recreational diving, and Good performance in the more aggressive tests. In the water, the regs are Good breathers in all positions. They also earned a Very Good rating for dryness in the swimming position and a Good for dryness in alternate positions. However, test divers' comments indicate that the Brut tends to free-flow a little in the heads-down position.

Test divers liked the lightweight second stages, rating them Very Good for comfort. Bubble interference was also rated Very Good when fitted with the extended exhaust tee (standard) and Good with the narrow exhaust tee (optional). Purging by blowing through the mouthpiece was easy and efficient, but a stiff purge cover made manually purging the regs a bit difficult.

|| |---| |

| | Sherwood Scuba Oasis| |

| | Sherwood Scuba Blizzard| Sherwood Scuba Oasis & Blizzard

> SIMULATOR SCORES: 13 out of a possible 20.
> ERGO SCORES: 46 out of a possible 70.

Another example of workhorse regs from Sherwood, the Oasis and Blizzard are virtual twins but with specific, namesake features. To prevent dry mouth, the Oasis offers two moisture-retention fins in its second stage. The Blizzard, designed for cold water, has the same fins, but they're coated with Teflon to prevent icing. There's also a heat sink to prevent freeze-up and second-stage free-flow. In both regs, the balanced first stage incorporates Sherwood's dry air-bleed system, and offers two primary-flow low-pressure ports to boost outlet pressure to both primary and octopus second stages.

Like their less-expensive cousins, the Oasis and Blizzard delivered Good to Very Good simulator performance, and were Good all-position breathers in the water. They remained very dry in the swimming position, while rated Fair for dryness in the heads-down position (averaging a Good overall rating for dryness). When it came to clearing using the blowing method, the regs provided a very easy, forceful purge. The purge covers allowed for stiff but effective manual purging.

Test divers liked the lightweight second stages."It's almost like it's not even there," commented one diver. However, the rather large Wisdom mouthpiece that comes standard on these models garnered mixed results: Half the test divers loved it, half didn't. All Sherwood regulators come with a free two-year replacement parts warranty, including hoses, mouthpieces, exhaust valves and diaphragms.

More Than $500

2004 Testers' Choices

The all-around top performers in this year's reg go-round, these three breathers delivered Very Good to Excellent simulator scores. They also earned Very Good marks in the most important ergo categories, with Scubapro's MK25/X650 stepping ahead with an Excellent for ease of breathing and Apeks' Black Pearl with an Excellent for ease of clearing.

|| |---| |

| | Scubapro MK25/X650| Scubapro MK25/X650

> SIMULATOR SCORES: 20 out of a possible 20.
> ERGO SCORES: 57 out of a possible 70.

Scubapro's MK25 balanced piston first stage, coupled with the new X650 balanced second stage, was this year's top performer, earning a perfect simulator score for the lowest work of breathing across the test board and the highest total score for ergonomic performance. It's the only reg test divers rated Excellent for ease of breathing in the swimming position, and it got Very Good scores just about everywhere else.

Test divers liked the first stage's low-pressure port swivel turret, which greatly simplifies hose routing. The dive/pre-dive switch is clearly marked, so you can tell at a glance which position you're in. It's also easy to use when wearing gloves. The same goes for the breathing resistance knob.

The MK25/X650 earned an overall Very Good rating for clearing, especially using the blowing method. However, test divers considered the purge cover to be excessively stiff, making it difficult to activate the manual purge. But this was the only drawback they found on a very sweet reg.

|| |---| |

| | Zeagle Flathead VI/ZX| Zeagle Flathead VI/ZX

> SIMULATOR SCORES: 20 out of a possible 20.
> ERGO SCORES: 55 out of a possible 70.

Hot on Scubapro's heels, Zeagle's flagship Flathead VI/ZX has a redesigned, environmentally dry-sealed first stage with "enhanced internal porting" and a new side-ducted cover on its ZX balanced second stage to better channel water. According to Zeagle, these refinements are intended to improve flow efficiency and smooth the delivery of air. Based on our test results, they hit the bull's-eye. In our lab tests, the reg turned in a perfect simulator score--Excellent across the board--and in the water divers rated it Very Good for ease of breathing in all positions. The reg also breathes very dry and stays that way, thanks to a very efficient purge system.

Test divers found both the resistance adjustment knob and the dive/pre-dive lever effective and easy to use, but the minuscule markings on the lever make it hard to tell what position you're in. Test divers reported the second stage was lightweight and comfortable, but men and womem were split on the mouthpiece. Men liked it; women found it a bit too large.

|| |---| |

| | Apeks Black Pearl| |

| | photo "A"| Apeks Black Pearl

> SIMULATOR SCORES: 18 out of a possible 20.
> ERGO SCORES: 56 out of a possible 70.

Apeks' Black Pearl is not only one of this year's top performers, it's arguably the best-looking breather of the bunch. Created to commemorate Apeks' 30th anniversary, the limited-edition Black Pearl's first stage (which is environmentally dry-sealed) features an investment cast brass body embossed with an image of a hard-helmet diver (see photo "A"). The balanced second stage has an attractive co-molded plastic-over-metal cover with a dome resin purge decal.

Both in the lab and in the water, the reg's performance is as good as its looks. Based on Apeks' ATX200, the Black Pearl delivered Very Good to Excellent work of breathing on the simulator. In real-world conditions, test divers rated it a Very Good breather in all positions. This reg is dry and very easy to clear--test divers considered the push-button purge the most effective manual purge system in this year's test bed.

The Black Pearl also earned a Very Good score for comfort, due in part to its Comfobite mouthpiece. The dive/pre-dive lever is easy to find and use, even when wearing gloves. So too the adjustment knob, which is slotted to make it easier to grasp. In addition to a limited lifetime warranty, Apeks offers a free parts replacement plan to original owners.

{mospagebreak}Very Good Performers

While they didn't collect quite enough points to earn Testers' Choice designations, these three regs are nevertheless ahead-of-the-curve performers. The Zeagle holds a slight edge over the Mares models on the simulator. In the water, all of them were rated Very Good for ease of breathing in the swimming position, for dryness in all positions, and for clearing, while the Mares models held the edge on comfort.

|| |---| |

| | Zeagle Flathead XP/ZX| Zeagle Flathead XP/ZX

> SIMULATOR SCORES: 19 out of a possible 20.
> ERGO SCORES: 52 out of a possible 70.

The newest member of Zeagle's regulator line, the XP uses the same first stage as the Flathead VI, only it's not environmentally dry-sealed. The breathing machine performance of both regs was similar in all RMV/depth categories except the most rigorous, where the XP lagged slightly. So too in the water. While both regs earned Very Good scores for ease of breathing in the swimming position and dryness in all positions, the XP lagged behind the Flathead VI in breathing performance in alternate positions. These differences in machine and ergo scores mark the distinction between the Flathead VI's Testers' Choice performance and the XP's Very Good performance.

|| |---| |

| | Mares V16/Proton Metal| Mares V16/Proton Metal

> SIMULATOR SCORES: 18 out of a possible 20.
> ERGO SCORES: 51 out of a possible 70.

If you're into metal, this reg really shines. The Proton Metal combines a highly polished chrome- and nickel-plated brass and stainless steel second stage with a balanced diaphragm V16 first stage via a preferential high-flow low-pressure port. According to Mares, the mesh grid on the face of the compact second stage allows water flow around the second stage diaphragm, minimizing free-flows when swimming into currents.

The Proton Metal is an all-around solid performer. With no user adjustments, the reg delivered Excellent to Very Good performance on the breathing simulator. In the water, it rated Very Good for its ease of breathing in a swimming position, dryness in all positions, ease of clearing and overall comfort.

|| |---| |

| | Mares V32/Proton Ice| Mares V32/Proton Ice

> SIMULATOR SCORES: 17 out of a possible 20.
> ERGO SCORES: 51 out of a possible 70.

Mares' flagship regulator is also all-metal, with heat retention and humidifying properties built into the compact second stage for cold- water diving. The unit we reviewed last year came from the factory with an improperly installed exhaust tee, so at Mares' request we re-tested it. While simulator scores were identical to last year, in-water tests showed improved results in critical ergo categories. The reg's ratings for ease of breathing in a swimming position improved to Very Good, as did its ratings for dryness. The biggest improvement, of course, was in bubble interference, as test divers upped the score to Good. Hooked to a serious-looking V32 first stage via a preferential low-pressure port, the lightweight second stage is streamlined and comfortable and offers a strong purge.

Good Performers

Both of these regs delivered Very Good scores in the simulator test that most closely represents recreational diving. However, the Deep Limit Brass wasn't able to reach beyond that, while the Maximus earned Good scores for breathing performance in the more aggressive intermediate test categories before reaching its limitations at our most rigorous RMV/depth level. In spite of this, the Deep Limit Brass remained a favorite among test divers, and the Maximus was rated among the best in minimizing bubble interference.

|| |---| |

| | Ocean Master Deep Limit Brass Plus| |

| | photo "B"| Ocean Master Deep Limit Brass Plus

> SIMULATOR SCORES: 4 out of a possible 20.
> ERGO SCORES: 54 out of a possible 70.

Testing the Deep Limit Brass was a challenge. The original reg Ocean Master sent us, which was put on the simulator and included in the in-water tests, turned out to be a prototype. Ocean Master sent us a production model to replace it, but, due to test schedules, we were only able to put this replacement reg on the simulator. However, since the prototype and the production model delivered near- identical work of breathing results on the simulator, we feel safe in assuming that in-water performance would also be identical.

The Deep Limit Brass has a unique twin-piston first-stage design, and a second stage with two 360-degree swivel joints located on the underside of the body rather than on the side. On the simulator, this reg rated Very Good at an easy breathing rate at 132 feet. However, the reg exceeded test parameters for work of breathing in every other simulator test.

In the water, the Deep Limit Brass (the prototype) was well-received by test divers. They deemed it a very easy and very dry breather in all positions, but found it a bit noisy. The reg also clears very easily using both purge methods. The reg received an overall Very Good rating for comfort, especially among women. One test diver called it "absolutely the most comfortable reg for divers with smaller mouths." However, test divers felt there were too many turns on the adjustment knob, and that dialing it all the way in excessively restricted airflow.

Although they look identical, the 2004 Deep Limit Brass is a substantially better performing regulator than its predecessor, which is also called the Deep Limit and was still available when we began this test. To tell the difference, unscrew the second stage cover and look inside. The air barrel on the 2004 is gray plastic instead of chromed metal (see photo "B"), and along its left side, up by the mouthpiece, there's a bypass tube. Earlier versions of the reg don't have this tube. The Deep Limit basic version has a plastic second-stage cover while the Brass Plus has a chrome-plated brass cover.

|| |---| |

| | Sherwood Scuba Maximus| Sherwood Scuba Maximus

> SIMULATOR SCORES: 10 out of a possible 20.
> ERGO SCORES: 41 out of a possible 70.

Sherwood's top-line Maximus offers all of the first and second stage features of Sherwood's other regs, plus a little extra. It's the only Sherwood reg with a second-stage resistance adjustment knob and dive/pre-dive switch. It's also fitted with a second-stage swivel and a longer supply hose that allows you to route the hose underneath your right arm rather than over your right shoulder.

The Maximus delivered Very Good to Good performance on the breathing simulator in the first three breathing machine tests, but it couldn't quite achieve the 198-foot test depth. It came close, but exceeded test parameters at 191 feet. The reg earned respectable in-water scores for ease of breathing in all positions. The standard extended exhaust tee was rated Very Good in preventing bubble interference. The Maximus earned only a Fair rating for clearing (an average of a Good rating for clearing via the blowing method, and a Poor rating for the manual purge due to an extremely stiff purge cover). Test divers also found the resistance adjustment knob effective, but rather stiff. They liked the size and shape of the second stage, but were split on the Wisdom mouthpiece in terms of comfort.

Missing in Action

All major regulator manufacturers/distributors were invited to participate in this year's new regulator review. Here is a status report of the major manufacturers who are not a part of this year's review:

> AERIS, DACOR, GENESIS, OCEANIC and POSEIDON did not have any new regulators available or listed in their 2004 catalogs, so they were unable to participate in this year's review.

> BEUCHAT and CRESSI-SUB did have new (or previously unreviewed) regulators listed in their 2004 catalogs but chose not to participate.

> SCUBAPRO didn't respond. It has two new regulators in its 2004 catalog--the MK25/X650 and the MK25SA/S600. The MK25SA/S600 was not yet off the production line at the time of testing, but the MK25/X650 was available. Because Scubapro is a major manufacturer with widespread U.S. distribution, we purchased one from a local dive store to test.

> ATOMIC AQUATICS and TUSA each have a new reg due to be released in 2004, but production models of Atomic's new Tx2 and Tusa's new RS350 were not available in time for this review. Look for them in future reviews.

> APOLLO SPORTS also has a couple of redesigned regulators slated for release in 2004, but they had yet to be released to the American market at the time of testing.

Workhorse vs. Racehorse

Some manufacturers design their regs to operate on the ragged edge of positive pressure. This often produces surprisingly low work of breathing on the breathing machine and near effortless breathing performance in the water. But it also tends to make the regs a bit "nervous," and prone to free-flow at inopportune times. To manage this skittishness, manufacturers often add resistance adjustment knobs to the second stages in order to allow divers to control free-flows and adjust breathing resistance as needed.

Other reg manufacturers direct their attention toward stability and simplicity. These workhorse regs often don't deliver quite as low work of breathing numbers on the simulator (although a human diver may not discern the difference), but they tend to be stable breathers and they don't need user controls. You just put the reg in your mouth and breathe.

Both designs are legitimate and highly successful approaches to regulator design. The one you choose ultimately comes down to whether you're a hands-on or a no-hassle type of diver.

Regs By the Book

Generally considered to be the best manual on regulator repair ever written, the new Regulator Savvy by Pete Wolfinger breaks down into two sections: the first covers the nuts and bolts of basic regulator function, the second applies this knowledge to the art of adjusting a reg for optimum performance. Together, they represent a rational connection between the know-how and the "know why" of regulator operation. The manual is presented in a three-ring binder with 187 heavy-stock glossy pages and more than 300 easily understandable illustrations. Any diver interested in how his or her regulator works would find this manual interesting, especially the first section. However, it's written for regulator technicians and not for do-it-yourselfers. $50. Web: www.scubatools.com.

Many Thanks

To Mike Ward of Dive Lab, Panama City Beach, Fla., for his work on the ANSTI breathing simulator; to George Perez of Sea Divers, Enterprise, Ala., for his technical support during lab tests; and to Express Divers, Long Beach, Calif., for dive services during the in-water portion of the tests.

2003 Testers' Choices

For comparison, here are last year's top performers and their scores.

Under $300

ZEAGLE ENVOY $299 > Simulator Scores: 20 out of a possible 20. > Ergo Scores: 47 out of a possible 70.

$300-$400

ZEAGLE ENVOY DELUXE $349 > Simulator Scores: 20 out of a possible 20. > Ergo Scores: 47 out of a possible 70.

OCEANIC 02 TECH $379 > Simulator Scores: 16 out of a possible 20. > Ergo Scores: 47 out of a possible 70.

DACOR EAGLE PRO DPD $399 > Simulator Scores: 17 out of a possible 20. > Ergo Scores: 45 out of a possible 70.

Over $400

ATOMIC AQUATICS B2 $699 > Simulator Scores: 20 out of a possible 20. > Ergo Scores: 57 out of a possible 70.

APEKS ATX100 $649 > Simulator Scores: 20 out of a possible 20. > Ergo Scores: 56 out of a possible 70.

APEKS ATX40 $469 > Simulator Scores: 20 out of a possible 20. > Ergo Scores: 53 out of a possible 70.

POSEIDON XSTREAM DIVE $655 > Simulator Scores: 18 out of a possible 20. > Ergo Scores: 47 out of a possible 70.