If you hunt down and watch Never Say Never Again (1983), you will know that US Divers was the regulator of choice for James Bond and his friend, Fatima Blush. No doubt some people still use that model.
Long-time subscriber Thomas Lopatin (Hopatcong, NJ) wrote to ask Undercurrent, "Back in 1988 I purchased a USD Pro Diver regulator, based on its rating by the U.S. Navy, that you published in an Undercurrent issue 'way back then.' It's been my primary regulator ever since! I've had routine maintenance performed on a regular basis, and it still breathes great.
"I would be interested in learning more about what significant improvements (beyond all the marketing 'hype') have been made to primary regulators since I purchased mine. Do the current ones breathe any easier? Do they hold up better between overhaul schedules, etc? Based on what I'm currently aware of, there have not really been any 'sea-change' design improvements that have motivated me to upgrade."
The diving trade was scandalized. Many retailers held large stocks of regulators they wanted to dump.
What Tom is referring to is a 20-page 1988 issue of Undercurrent in which we reproduced the full 1987 U.S. Navy regulator tests, revealing that many sport diving regulators were seriously deficient as a diver approached 99 feet (30m), or even as shallow as 66 feet (20m), especially if he or she had to breathe hard. His USD Pro was one of the top regulators by those 30-year-old standards and is probably just fine today for the conservative sport diver, though modern regulators breathe much easier.
In 1987, 26 of 43 models tested by the Navy didn't pass muster, including models from Scubapro, US Divers, and Poseidon. Only eight were superior and safe for all levels of sport diving. The Navy tests were not circulated by the industry, so that we made the tests public was of great concern to the manufacturers, and we received a heavy-handed letter from Performance Diving, a now-extinct company, that threatened to sue us for our reporting. We didn't back down, but no other publication picked up the tests, so they remained largely a secret known only to Undercurrent subscribers.
However, in the UK a few years later, regulator testing began to go public, and eventually the results helped usher in new European legal standards that today assure us that regulators even in the U.S. are, indeed, safe, which they weren't in the 1980s. Here's what our Senior Editor, John Bantin, has to say:
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While I was Technical Editor of Diver Magazine in the UK, I started publicly upsetting the regulator manufacturers with my honest in-water comparison tests. One of the first I published, back in 1990, really set the cat among the pigeons!
At that time, there were plenty of bad regulators available, but experienced divers swore that the Swedish-made Poseidon Cyklon was the best. At the same time, a new regulator was produced in the north of England by Ken Ainscough, who owned a small engineering company. Since I was a believer in the Cyklon, I devised a test to demonstrate how this untried newcomer to the regulator market would be a poor performer by comparison.
I fitted four second-stages of this new regulator to one first-stage, and with four test divers (each equipped with their own tanks and regulator), we descended down the line to determine at which point the test regulator was unable to feed to all of them the air they needed. The idea was to replicate just one diver who for some reason -- panic, current, etc. -- was working extremely hard to get air.
I was shocked to find that at 180 feet deep (55m), the new regulator was supplying air better to each of the four divers breathing at once than when they switched to their individual regulators! I wrote the story, Diver Magazine published it, and the rest is history.
And, the regulator I presumed would hold up, but in fact outperformed the others, was the first of a new range of Apeks regulators.
The diving trade was scandalized. Many retailers held large stocks of regulators they wanted to dump. The boss of Poseidon at that time, Thomie Hjalmner, was so outraged when we published the results, I received a lawyer's letter from him. (Under English Law, as in America, if it's true, it is not libelous). It didn't stop me, and I went on to do the same with other well-known regulators. We soon discovered which regulators were the best and those that were not. The diving trade in those days hated these revelations.
At the same time, British engineers Ian Himmens and Stan Ellis proved staunch allies. They produced the first ANSTI machine, which, besides backing up my in-water experiences, could measurably test regulators for their breathing efficiency. It used a turnkey system that plotted the inhalation and exhalation effort together with the effort required to initially pull open the valve, producing an easily understandable and quantifiable graph.
Over the years, the ANTSI tests became standardized and accepted. While there was no independent effort in America to ensure overall that regulators were safe for divers -- Gosh, how the American dive industry abhors regulation -- the EU realized the danger apparent for individual divers and required that all regulators sold in the EU must meet performance requirements established by ANSTI testing.
And thanks to that, American divers, even with no independent body to oversee the safety of their equipment, have benefited greatly. Today, most regulators are made or sold in Europe, and these companies sell their ANSTI-approved regulators in the U.S. There may be a few regulators sold in American that do not meet the ANSTI standards, but they do not carry the telltale CE-mark of EN250 or come with a CE-EN250 certificate. EN250A means it's certified to work in conjunction with an octopus rig under the same conditions and in water colder than 10°C (50°F). You should check that. It may be hard to spot where it is engraved.
To get more technical for a moment, to meet the EN250:2000 standard, the overall work-of-breathing has to be less than 3.0 joules/liter with a respiratory pressure of plus or minus 25mbar, with no measurable spikes, at a breathing rate of 62.5 liters per minute (25bpm) at a depth of 165 feet (50m). That's with an air supply pressure equal to 725 psi (50 bar).
It's amazing what you get used to. Most regulator designs now achieve a work-of-breathing of less than 1.0 joule/liter. Nowadays, comparison with a modern regulator might make your old USD Pro Diver feel as if it breathes like an asthmatic in a smoke-filled room! You need to try a new regulator. Thanks to EU regulation and ANSTI, if you buy an approved regulator, you can be certain it's a good one (unless you've bought a rare faulty one that needs to be replaced).
Many top-end regulators include "value-added" features like a breathing resistance adjustment knob so that you can increase the inhalation effort needed to 'crack open' the second-stage valve. But, why would you need that? Many regulators are so highly tuned, they need a device to stop the exponential free-flows when suddenly subjected to an increase in pressure, as happens at the surface between air and water. This is usually something that temporarily interferes with the Venturi effect within the second-stage and is often called a Venturi +/- or a Predive/Dive switch. Mares regulators use a patented bi-pass system instead.
As for maintenance, manufacturers still recommend an annual service apart from one -- Atomic Aquatics. Its regulators use a clever design that requires servicing once every three years. However, this is reflected in the purchase price. It's pricey.
So, to answer Thomas Lopatin's question, yes, Thomas, it's time to upgrade. In fact, any diver still using a regulator from the last century is likely diving with an underperforming piece of equipment. Unless you confine your dives to 60 feet in benign water, it's time to part with your old friend. In an emergency, it may become your enemy.
It's not all as it seems: People cheat. In recent years we've got used to the fact that if a product bears the CE mark, it is safe. Unfortunately, there exists a very similar mark, which the majority of consumers and even sellers may see as the CE mark of the European Union but actually is something completely different. This "CE" mark means "China Export" meaning the product was manufactured in China! Various organizations believe that this similarity is not a chance coincidence and that it expresses an aggressive approach to sell into the European market without applying the right standards.