Back in 1989, Diver magazine used the latest technology, the ANSTI breathing machine, to test most of the regulators then sold in Britain. It's inconceivable to think it now, but some of those regulators proved not good enough even for 30m diving.
When we printed the results of our tests, several regulator manufacturers and distributors complained bitterly, and some even withdrew their advertising from the magazine. Some also withdrew their products from the market. Others made sure that when we conducted the same exercise less than two years later their products were up to the mark. By this time nearly every regulator tested was good enough for 50m plus!
In September 1993, we reviewed a new regulator from the British manufacturer Apeks. We hit upon the idea of rigging it for four divers at one time and descending progressively deeper with it in the sea until it failed. Expecting to 'beat the valve' at some point, we were surprised to reach 50m with it still giving as much air as four people could possibly ask for. Some other manufacturers and distributors thought that the report in Diver of this test gave Apeks an unfair marketing advantage, so in April 1994 we published a side-by-side comparison of eight top-of-the-range regulators from well-known makers, breathing four-up. In no case were we provided with insufficient air, even at 50m plus. Amazingly, even a cheap regulator, added to the line-up for comparison, was able to adequately supply four large men, breathing in unison, as hard as they could.
You would have thought all the manufacturers would have been delighted. However, there were differences between the way in which each valve performed, and the four test divers expressed personal preferences. When we reported the findings to our readers, several manufacturers again took umbrage at not being top of the list and withdrew advertising. Now, regardless of more possible wrath from manufacturers, we have selected a total of 18 regulators from the current equipment ranges of 10 major suppliers, and we have tested them both by machine in the laboratory and in open water using a panel of divers.
We asked each company to supply a first stage with two identical primary second stages. However, design constraints meant that certain regulators could be supplied only with a primary second stage plus an octopus second stage. One company declined to supply us with any of their regulators, so we purchased one of their current models from a dive shop. There are now European standards for breathing regulator performance (EN250 and EN250 For Cold Water) achieved using a machine test. Most of the 18 regulators tested have been certified to one or both of these standards; others are currently awaiting certification. A copy of the relevant certificate should, where appropriate, be included with each new regulator bought at dive shops.
Our machine tests were staged courtesy of A.P. Valves, Helston. A.P. Valves is a company which uses an ANSTI machine for spot checking the performance of its own AutoAir, an alternative breathing source fitted to Buddy BCs and used in conjunction with the diver's own regulator. However, it does not make a regulator of its own.
Using the ANSTI machine, we tested each regulator, in water, with 75bar supply pressure at a rate of 25 breaths per minute and a tidal volume of 2.5 litres. This gave a ventilation rate of around 63 litres/min. Machine pressure was then increased to the equivalent sea water depth at which either the inhalation or exhalation pressure reached 2.5 kilo-Pascals, or the work of breathing reached 3 Joules per litre. This gave us our maximum-depth rating.
For our open-water test, the divers were selected both for their wide range of diving experience and their impartiality. The ANSTI results were kept secret from them prior to the test. We went to the Egyptian Red Sea, to The Tower dive site, near to Sharm el Sheik.
Sharm, with nearby Nama Bay, is one of the most popular diving resorts in the world. It is blessed with clear water, relatively calm seas, and a medical centre with a state-of-the-art hyperbaric chamber for use in the event of the worst happening. Added to that, it's within easy reach of Britain, with regular flights from Gatwick. Our agents, Goldenjoy Leisure, made special arrangements for our 100kg of excess baggage.
The Tower had been used for our previous (1994) in-water tests. It offers deep water, with a wall and easy access from the shore. This year, the Anemone Dive Centre, based in Nama Bay, provided us with twin 12-litre cylinders for the test, plus air supplies, transport, emergency oxygen equipment, and shore support.
Each of our four test divers, plus myself in the role of superviser, dived with twin-sets rigged to technical diving stab jackets, such as the Buddy Trimix, loaned by A.P. Valves. This set-up enabled each of us to rig two regulator first stages to our tanks. Each of the first stages was fitted with two second stages as already described. Diving in buddy pairs, the test divers thus had, between them, four different regulators on any one dive.
We descended as a group to 40m, where each buddy pair would use each of their four regulators in turn, with one of each pair of second stages in use as an octopus. When invited to, I would offer the two second stages of the additional regulator I was carrying. In this way, each pair of divers could compare five different regulators side-by-side, at 40m, and find out how they performed even while tandem breathing.
Some regulator second stages had additional knobs and switches. These generally fell into two categories: venturi adjustment levers, and breathing resistance controls. The venturi lever is used as a way of reducing the tendency of a regulator to free-flow when not being breathed from. (Some regulators use other design solutions instead.) The resistance knob is used to vary the effort needed to crack open the air supply at each inhalation. People who dive deep often like to be able to increase the breathing resistance. Our test divers had time to check out the effectiveness of these 'extras'.
During the dives, the test divers made notes on their submersible slates, and I was pleased to see that there appeared to be no sign of nitrogen narcosis, each diver performing the allotted task and making notes in a coherent manner.
Once the first pair had finished with my spare regulator set-up, I would move to the other pair and allow them to breathe from it. Naturally, all this took time at depth and we needed to make slow ascents and long decompression stops before surfacing. Total dive durations tended to be between 50 and 90 minutes each. We all used computers.
After the first dive, each pair elected to keep one regulator set-up for comparison with the four new regulators used on the next dive.
We made a second dive each afternoon to a maximum depth of 20m for a photo shoot. This extra time in the water gave the test divers plenty of opportunity to try all the regulators at shallower depths.
Diving in this way on five consecutive days allowed us to permutate all the regulators between the test divers at 40m. Naturally, the Red Sea provided some entertainment. During our dives we were joined by all manner of marine life, including a turtle, a manta ray adorned with the most enormous remoras we'd ever seen, and, unbelievably, two 3m silky sharks. It must be stressed that every regulator in our test functioned in a usable manner. There was no question of any of them 'failing'. However, all the test divers were surprised just how different each of the regulators proved to be.
We retired each evening to our apartment at the Hilton Residence in Sharm, where we discussed the day's results, and decided which regulators should be rigged for the next day's 6am start. Although I interviewed each diver separately, I found, to my surprise, that their views more or less coincided - not only with each other, but with the ANSTI machine results! This, in ascending order of price, is what we discovered.
The results of testing the first ten of eighteen regulators on the ANSTI breathing machine and on the seabed
The least expensive regulator in our test was the US Divers Conshelf 22 (£172). With its diaphragm-design first stage, this regulator made it to 58m before it started to fail the criteria set for the ANSTI machine. At this depth, it developed a flutter at the start of each inhalation.
We saw the Conshelf 22 as a good old-fashioned regulator. The layout of the hoses from the first stage was not as good as some of the other models because of the radial layout of the four medium-pressure (mp) and single high-pressure (hp) ports. This caused some hoses to take a rather unnatural path and put undue stress on them. There were no hose protectors at the first-stage end to help with the problem.
Because the primary second stage uses an over-sized port, Aqua-Lung (UK) sent us a US Divers octopus rig. This meant that our test divers had to swap the second stages between them.
George Brown thought that the Conshelf 22 gave a good-to-average breathe.
"It needed a bit of a drag for inhalation, but in a plethora of valves with knobs and switches it was a pleasurable no-nonsense bit of kit."
Joanne thought that it made it very easy to inhale, whereas Tamara found it quite hard to breathe from and very loud. George Buxton felt that it was OK; but it did, he thought, seem a bit noisy.
Everyone was unanimous in their dislike of the Spiro/US Divers Comfobite mouthpiece. It was just not comfy! In fact, we all preferred to use it the wrong way up, and opted to change it for subsequent dives.
The rather modest Oceanic Alpha combined with an Oceanic Balanced Piston first stage (£180) was a great surprise to us all. Economically priced and probably intended as a school or pool-training valve, we found it to be one of the best performers. The simple turret-style first stage has a neat matt finish. Its two hp ports are well positioned, and there is a good hose protector to the mp hose, which is connected to any of four ports sensibly positioned around the revolving turret.
This regulator does suffer from the characteristic head-clouting problem of most turret designs, but we got round this by simply inverting it when we mounted it on the tank valve.
The Alpha second stage is pleasantly light and compact. It tended to pick up pebbles in the diaphragm cover (a hazard of shore diving from a beach), but this cover is easily removed and reveals a beautiful second stage lever mechanism. George Brown thought it was "great". The all-round performance was good, and although he had a little problem with grit picked up on the beach, he found that the ability to take the second stage apart, even in the water, was a terrific advantage. When he did take it apart, he said he liked what he saw inside.
Joanne didn't like this one at first. She said that it made her feel rather claustrophobic because she had to breathe so hard. But what a difference when she made a second dive using the alternative second stage! The varying impressions of our test divers seemed to suggest that different ports gave different performances with this regulator's second stage.
Tamara thought that this regulator was the lightest breather of all those she tried that day. Very good and very compact. George Buxton had no problem on any part of the dive, but thought that his second stage needed more 'pull' than some of the others.
The Oceanic Alpha surprised everyone with its performance on the ANSTI machine. It appeared to give a very even breathe, only failing once it had passed a depth of 76m. If you use one, make sure you choose the best performing port for the second stage!
The Apeks TX40 (£183) has an identical first stage to the Apeks TX50, but lacks a breathing resistance (BR) control to the second stage.
We loved the dry-sealed diaphragm design of the first stage, the turret of which didn't protrude high above the scuba cylinder - avoiding discomfort while swimming horizontally in the water.
We also liked the clearly marked and easy-to-use venturi switch. If you use one of these as an octopus, anyone can easily see how to switch it from minus to plus, regardless of what sort of hurry they might be in.
Our ANSTI machine was beaten by this valve. We took it past 80m and the regulator still performed as smoothly as ever. Our test divers were enthusiastic.
George Brown said, "great!!!" (insisting that I wrote down the three exclamation marks in my notes). He thought it was, dry, easy, and comfortable. He said it performed admirably when the venturi switch was in the minus position and even better when he moved it to the plus. He found it very easy to switch. Joanne said, "I like it."
Tamara said
, "I'd never even heard of Apeks regulators before. However, the TX40 gave a very nice breathe. Everything was very OK."
George Buxton said,
"When I tried the TX40, I thought it was marvellous. The other four rigs my buddy and I were equipped with on that particular dive seemed poor by comparison."
The US Divers Conshelf SE3 (£196) is a diaphragm-type regulator. It has a conventional-looking first stage with a nice hose protector, but suffers from typical problems associated with radially arranged ports. Some hoses always seemed to end up pointing upwards and need tortuous routing with resultant stress near to the first stage.
George Brown found the mouthpiece (another Comfobite) particularly awkward. The diaphragm had a noisy action which did not inspire him with confidence.
"I was particularly disappointed, because I was about to buy one!", he said.
Joanne said that this regulator seemed particularly uncomfortable. She noticed how much it fluttered.
"The discomfort of the mouthpiece dominated my thoughts."
Tamara thought that it gave an easy breathe, but had reservations about the Comfobite mouthpiece.
George Brown reported that the Conshelf SE3 gave a very steady breathe. It was average. It was nothing special.
The ANSTI machine revealed a fairly even performance which started to decline once the regulator reached a simulated sea-water depth of 60.1m. If you want one of these regulators, don't be put off by the unusual mouthpiece. You can replace it with a normal one at minimal cost.
From France, the Beuchat company sent us a selection of regulators, but failed to understand our requirement for two identical second stages. I therefore fitted a VS8 second stage to a Beuchat VS10 (£198).
We found that this regulator's diaphragm first stage was one of the few revolving-turret designs which it was possible to use comfortably the right way up. It's a heavy design and looks very well made. However, with a turret like this in use with lots of hoses, there's always bound to be one hose in the 'wrong' position.
The second stage looked conventional, even a little ordinary, but was well made with a nice-size exhaust deflector and BR adjustment knob.
George Brown thought that the Beuchat VS10 had a good bite and was better than some.
"The BR knob appeared to make no difference at depth, but there was a discernible difference in the shallows."
Joanne thought that this valve was excellent, quiet and comfortable.
Tamara thought it was "average".
George Buxton reported that with the adjustment knob on maximum flow it felt it had more breathing resistance than any of the valves he compared it directly with under water. I definitely became harder on the minus setting.
"When I was shallow it started to free-flow during a head-down descent, so I had to de-tune it as I went."
Unfortunately, the Beuchat regulators arrived too late for our ANSTI machine test session.
The piston-design Sherwood Blizzard (£199) suffered from the fact that it didn't sit comfortably on all the cylinders we were using. It certainly didn't like those tank valves converted to international A-clamp with screw-in DIN inserts.
We wondered why the first stage had five mp ports but only one hp port, but noted that the Blizzard had particularly nice hose protectors at both ends of the mp hose supplied. This hose is also angled at its junction with the second stage, which made for a very comfortable 'sit' in the mouth, without hose tug. The large purge button was the most clearly defined of any of the regulators we tested.
George Brown found the Blizzard's deep-water performance a little disappointing. It was a dry and comfortable breathe, but more effort was required to inhale than with some of the other regulators.
Joanne found it to be a bit noisy. She found the air to be on the cold side, but, being a confirmed warm-water diver, this was her preference.
Tamara found that when her cylinder was full, the regulator breathed easily; but later in the dive she detected a distinct flutter, particularly when she faced downward.
George Buxton said he found the performance very similar to, or better than, that of the US Divers Conshelf SE3. Sherwood first stages have a dry-bleed system. This means that there's always a small trickle of air emanating from the mechanism, which tends to make those not 'in the know' suspect a leaking O-ring.
The ANSTI machine test showed the Sherwood Blizzard to be good for 60.6m - at which point it started to flutter dramatically at the beginning of each inhalation.
Our ANSTI machine prize for fluctuating inhalation pressures must surely go to the Dacor Quantum (£199), which sent the plotter reverberating all over the print-out of the pressure/volume diagram. This regulator did, however, manage to meet the criteria to a maximum depth of 58.7m.
In the water, George Brown thought it to be very dry and a good breather.
Joanne thought that it was nice and compact, and comfortable in the mouth.
On the other hand, Tamara thought that it was not one of the better breathers. She found it difficult to purge with the mouthpiece - "a little on the hard side". She felt that her breathing was slightly restricted.
George Buxton thought that initial breaths felt wet even when purging. The air seemed to feel cold when compared with that of other regulators. He felt a 'pitting' sensation from a slight spray on his tongue in the shallows, but then again he felt there was nothing wrong with the breathing.
The first stage of the Quantum looks a bit like something from a modern central heating unit. We liked the way it routed the three mp hoses. There was one hp port. However, some of the threads on these ports were unusual, probably in some misguided effort to persuade purchasers to use this regulator with a dedicated Dacor BC.
The second stage of the Quantum tilts down away from the mouth, is very compact, and has a cowling made from a soft impact-absorbing material. It integrated the purge button with the exhaust port (which gave Tamara some problems). This arrangement also meant that foreign bodies could easily enter the mechanism.
The cowling was secured rather crudely with a cable tie to the mp hose, a modification which suggests that there may have been problems with the attachment to the body of the second stage.
The Oceanic Delta with the Oceanic Balanced Piston first stage (£203) went to the limits of our ANSTI machine (78m), continuing to function smoothly and without too much effort.
This regulator has the same first stage as the Alpha we tested. This is a simple piston design with two hp ports and four mp ports arranged on a turret. As previously, we preferred to rig the turret pointing downward in order to avoid the occasional clout on the back of the head from the first stage when swimming horizontally.
The Delta second stage is a lightweight all-plastic design which has a BR control (or de-tuning) knob which cannot be overtightened.
In the water, George Brown thought that this was "a damned fine regulator". It tended to free-flow when the de-tuning knob was set at anything less than the minimum setting; but, otherwise, he found it very comfortable.
Joanne, on the other hand, said that she found it not very comfortable at all, although it gave her a good air supply. Tamara said she found that because the de-tuning knob had no stop, it got her a bit confused in setting it.
"But the breathe was very good."
George Buxton said more or less the same. He thought that it breathed extremely easily and smoothly. The BR knob had an enormous range, but there were far too many turns from fully open to fully closed.
The Spiro Supra XP (£216) has a diaphragm-type first stage which we thought was one of the nicest for routing the hoses from. The primary second stage uses an extra-wide mp port. There are three other mp ports and two hp ports available.
The first stage is very nicely machined, but the rather chunky A-clamp knob could be confused with a a tank valve knob and undone by mistake by another diver unfamiliar with a rig as complex as those we were using. Although the XP second stage of the Spiro Supra looked massive, it turned out to be very light in the mouth. The exhaust deflector's exits were widely spaced.
George Brown thought that this regulator was one of the better performers at depth. He said he'd recommend it to anyone. Joanne said she thought it had a really comfortable feeling. Under water, it was like breathing fresh air!
Tamara liked this regulator very much despite misgivings about the massive dimensions of the second stage. However, as usual she hated the Comfobite mouthpiece.
George Buxton actually preferred the Spiro Octopus rig to the breathe of the Supra primary second stage. But he thought they were both good, if not special. He admitted that he was probably negatively influenced by the mouthpiece. Our divers were inclined to remove the mouthpiece, invert it, or replace it with the more normal type found on the Spiro Octopus.
In the ANSTI machine test, this regulator met our criteria to a depth equivalent to 61.9m of sea water.
The Scubapro Mk20/R190 (£220) represents this company's latest version of a piston-type regulator for which they are well known. It uses the new Mk20 first stage combined with the familiar R190 second stage. Scubapro's previous first stage - the Mk10 - became almost standard issue in many parts of the world where regulator servicing is not the most sophisticated. It became the regulator equivalent of the Kalashnikov rifle. It wasn't necessarily the best performer, but you could use it and abuse it and it still went on working. We'll have to wait to see if the new Mk20 follows this tradition.
The ANSTI machine showed a great difference between the two (identical) Scubapro second stages. But both performed remarkably well to a depth limit of 76.8m - where one reached the limit of inhalation pressure. The other second stage then carried on to beat the machine, needing only 1.29kPa of inhalation pressure (when the acceptable limit was 2.5kPa), and a total work of breathing of only 1.89 joules/litre (when the acceptable limit was 3.0 joules/litre).
We liked the simplicity of the R190. The absence of knobs and twiddly bits is great - providing you don't find that your regulator constantly goes into free-flow. The R190 does, however, come with a venturi (plus and minus) switch - but more of that later.
The Mk20 first stage is a sturdy piston-type design with a turret which we chose to fit inverted on the scuba cylinder. George Brown and Joanne agreed that this was a good breather: dry, comfortable, and reassuring. Tamara experienced some problems with free-flow on the way down, but once she got to the maximum depth (40m), the regulator settled down to give a very easy breathe. She did, however, find the mouthpiece a little uncomfortable.
George Buxton thought it was harsh and noisy. He couldn't read the position of the venturi switch under water because it was black on black.
"If you have switches, it's important to be able to read them,"he said.
NEXT MONTH:
our extensive survey of regulators continues. We put the Spiro Pioneer, Apeks TX50, Sherwood Maximus, Mares MR12 Voltrex, Poseidon Triton 2000, Dacor Extreme Plus, Scubapro Mk20/G250 and Mares MR22 Abyss to the test, both in water and in the laboratory.
George Buxton is a veteran of our previous in-water regulator test, and as such proved invaluable in contributing to improving our methodology based on this experience.
Aged 49, George learned to dive in 1978 at Walthamstow College and joined Hoddesdon BSAC. Achieving his Advanced Instructor badge in 1989, he was awarded the BSAC First Class Diver qualification in 1990. He is a Nitrox Instructor (TDI and BSAC), and has made more than 1800 dives in the UK, many part of the Red Sea, the Maldives, Bahamas, Turkey, France, Spain and Malta. His main interest is underwater photography with a leaning to deep diving "where a good regulator is essential".
Tamara Double has been diving since 1978. She learned to dive at the Frobisher Institute (ILEA New Cross), and became a British Sub-Aqua Club Advanced Instructor in 1984.
She has been working as a diving instructor/guide since 1980, when she met her husband Alex in the Sudan. After a short period with the London Underwater Centre, they both returned to the Red Sea to work in Safaga, Egypt.
Between 1986 and 1992, Tamara and Alex ran the Red Sea liveaboard Lady Jenny V. After a short period working with other vessels, Tamara returned to Britain to work on her forthcoming book, provisionally entitled A Thousand Miles of Red Sea Diving. Her extensive experience in the Red Sea has enabled her to log more than 4000 dives.
George Brown (44), learned to dive with Edinburgh BSAC in 1969, and has been doing it ever since. He attained BSAC First Class Diver in 1984, and became a BSAC National Instructor in 1988. A professional diver (HSE Part 3) working as a civil engineer with the Highlands Council, he dives daily. Besides Scotland, he has, over the years, dived for leisure in many other parts of Britain, the USA, Bermuda, the Red Sea, Norway, Germany and Ireland.
As BSAC Expeditions Adviser, he has dived in Canada, Norway, and the Red Sea. He won the BSAC Expeditions Trophy for his expedition to Rockall in 1986. For the Instructor Training Scheme Overseas he has visited Gozo, HongKong, Brunei, Australia, Ascension Island, the Falklands, Oman, Germany, and Gibraltar.
Joanne Holland, is 25 and qualified as a PADI Open Water Diver in August 1995. However, working full-time at Nama Bay's Anemone Dive Centre has given her a lot of experience in a short space of time. She is currently awaiting her Advanced Open Water Diver certification.
Originally from Manchester, she came to Sharm el Sheikh to take a break from working for an MSc in Health Services Research at Erasmus University in Holland.
PADI divers are not qualified to make dives requiring decompression stops. However, Joanne understood basic decompression theory and was able to undertake the dives in a competent and intelligent manner. Despite her youth, she stood the course and was resilient enough to get up at 6am every day to be with the rest of us.
John Bantin (49) is well known to readers for his Diver videos and numerous articles written since he took up diving in 1983. He became Chief Correspondent for DIVER in 1995. He is qualified with several training agencies, and holds qualifications including BSAC Advanced Instructor, TDI Rebreather Diver and PADI OWSI.
He is not afraid of controversy but always writes about diving from first-hand experience. He believes in doing his homework first.
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