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What it Takes to Supply Air Refills on a Liveaboard

Experts worry about the compressor on a liveaboard so you don't have to.
By Roger Roy | Updated On May 19, 2021
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What it Takes to Supply Air Refills on a Liveaboard

Air compressor

Liveaboard air compressors often require customization to fit in retrofitted vessels.

Courtesy Nuvair

Talk to a diver just back from a dream liveaboard adventure and you’ll hear about the diving, the food, the service, the tropical sunsets. The compressor system, not so much. Yet without a reliable source of quality, high-pressure breathing gas, it wouldn’t be much of a dive trip.

To find out what’s required to keep the gas flowing on liveaboards, we talked to Glenn Huebner, CEO and founder of Nuvair, an international provider of compressed-air systems for more than 30 years.

Q: Having been belowdecks on a live­ aboard, it doesn’t seem like a very friendly place for sensitive machinery. What’s involved in designing and building a compressor system for a liveaboard?

A: You’re right. Belowdecks on most liveaboards is an unforgiving environment. Cramped, hot, humid and poorly ventilated is the rule of thumb in these compartments, making it difficult for machinery to work efficiently without significant modifications. Ocean-going vessels add the additional concern of corrosion.

Off-the-shelf compressors—like what you would see in a dive shop—rarely work on liveaboards. We evaluate each liveaboard as to air/nitrox delivery requirements, and custom design an equipment layout based on available footprints. That regularly requires equipment installation on multiple decks. Our team designs everything from the air intake snorkel to the scuba tank fill whips.

Depending on the application, our marine compressors are built on a stainless-steel chassis and can be either water-cooled or air-cooled. An optional refrigerated air dryer is a good investment on poorly ventilated air-cooled systems. Dryers extend air filter life and reduce internal corrosion of compressor components. Stainless-steel multibank fill panels can handle different delivery pressures and gas mixes.

Q: With the variety we see in liveaboards—modest­size sailing vessels to large yachts, monohulls, catamarans, trimarans—it must make every com­ pressor design job different.

A: Many liveaboards were not purpose-built for diving, and that means retrofitting high-volume, high-pressure breathing-air compressor systems into compartments with oddly shaped and disjointed open spaces. The team at Nuvair has decades of experience designing and fabricating compressor systems for any size vessel, whether a breathing-air system was an afterthought or part of a new liveaboard vessel design.

Q: It’s been a real benefit to divers that now we see liveaboards even in the most remote locations offering nitrox on board; what sort of technology has made that possible?

A: At Nuvair, our semi-permeable membrane systems generate enriched air nitrox from ambient air, thereby eliminating the need for partial-pressure blending, booster pumps or cylinders of dangerous high-pressure pure oxygen. In essence, the membrane allows oxygen molecules to pass through while expelling a portion of the nitrogen molecules. Our low-pressure nitrox system delivers up to EANx40 to a high-pressure compressor for delivery to scuba tanks or storage cylinders.

Our fully automatic series of Voyager water-cooled nitrox systems are a great example of how a turnkey package can deliver 22 percent to 40 percent enriched air nitrox. Imagine if liveaboard guests diving the same site but on different profiles wanted EANx29 and EANx36 for dives to 126 feet and 95 feet, respectively. Our system allows tanks to be filled with custom nitrox mixes, giving divers the best nitrox mix for their intended maximum operating depth. And, without partial-pressure blending, tanks do not require oxygen clean servicing.

Q: The technology in this field has progressed so much in recent years; what sort of technical advances can live­ aboard divers expect in the future?

A: We are working on upgrades to the Nuvair Nitrox Manager to allow deck crews to select nitrox blends by using a touchscreen compressor controller. The screen will also provide full control of the compressor components, system status indicators and customizable pressure delivery.