Surface Dive Deck Snorkel
For underwater maintenance and shallow-water sightseeing around the boat, the 12-volt battery-powered Deck Snorkel is a handy and compact alternative to scuba gear.
For Practical Sailor's last anchor test, reported in the December, 2003 issue, we had a diver/observer sitting comfortably on the bottom, 10 feet down, in a wetsuit top, for the better part of six hours. He was breathing compressed air, but not from a scuba tank. He was using a Deck Snorkel from a company called Surface Dive (it's an Australian product, via U.S. representatives in Ohio). The Deck Snorkel isn't new, but it was new to us, and we were very impressed by it, both in the clear Florida waters where we did the anchoring tests, and the colder, murkier waters of Long Island Sound. In fact we bought the evaluation sample and plan to use it on several future underwater projects.
It won't be long. Like everyone else, we need to scrub boat bottoms, clear fouled props, inspect pilings and mooring chain, locate anchors, find winch handles, wrenches, glasses, and wallets that fall overboard— and of course we like to just go out and have a look around every once in a while.
The Deck Snorkel is very simple. It uses a small, oil-less, 12-volt compressor, mounted in a plastic tackle box, to pump air through a hose to a floating plastic accumulator tank (air reservoir). Another hose comes out the far side of that tank and runs to a standard scuba regulator mounted on a webbing chest harness. That's the whole show. The power cable with clips is 16 feet long—plenty to reach most mounted house batteries. The hose from pump to accumulator tank is 20 feet long, and the hose from accumulator to diver's harness is 28 feet. Realistically, that gives the diver a maximum depth of about 23 feet. The hoses, accumulator tank, and harness rig are all equipped with quick-connect fittings (which should be kept scrupulously clean, by the way).
Hook the compressor to a 12-volt battery on board your boat with the provided battery clips, flip the switch to turn on the compressor, wait a few moments for the accumulator tank to get charged with air while you're strapping on the harness and spitting in your mask, and you're ready to go overboard.
The rig works at 18 psi—much lower than a scuba rig or engine-driven compressor, and eliminates the danger of the compressor's air intake picking up fumes and carbon monoxide from an engine-driven system.
Three other things about the Deck Snorkel—the single-diver version, anyway—are outstanding. First, the whole rig, stows in a duffel and weighs 29 pounds. Second, you don't need to worry about filling tanks. As cruising sailors know, that chore can be so onerous that carrying scuba gear is often not worth the trouble. Third, you get a tremendous amount of breathing time. Our anchor observer did eventually draw down a single 12-volt deep-cycle battery (Group 24, 90 amp hours) after almost six hours underwater (hey, he got a lunch break), but the battery still had something left after the diver had actually turned into a prune.
The compressor draws about 11 amps; thus, if you have a battery with 65 usable amp-hours, you would get almost six hours. However, that’s if you're sitting still on the bottom and breathing like a clam. If you're swimming around and breathing hard, four hours of time would be more realistic.
The rated air inflow is two cubic feet per minute, continuous—more than enough for moderate breathing. In our Long Island Sound experiments, we did a panting test while sitting on the bottom at about 8 feet, and tried to overwhelm the accumulator. While we could feel an increase in difficulty, we were never short of air. In moderate use, breathing was virtually effortless through the provided regulator—a far cry from our ancient ScubaPro regulator, in which the demand valve in the second stage has to take a vote before opening.
Surface Dive carries several variations on the Deck Snorkel theme, although all are based on 12-volt compressors. You can buy additional hose and regulator kits to accommodate a second diver, or a double compressor package, or different hose extensions, or a boat-independent unit, called the Power Snorkel, in which both the compressor and rechargeable battery are encompassed in a float that you tow along on the surface. There's also an Extreme Snorkel, which will allow one diver to a depth of 72 feet, two divers to 50 feet, or four divers to 16 feet.
This brings up the matter of safety. No license or certificate is required to use the Deck Snorkel, and the dive hose on the basic rig won’t allow the diver to go deep enough, long enough, to require decompression stops. This isn't to say, though, that you can't kill or seriously injure yourself using this rig. Breathing compressed air at any depth involves a risk. Failure to exhale on ascent is the big one: If you breathe compressed air under water, then ascend, the air in your lungs expands as the pressure decreases. If you don't exhale the air as you rise, you'll stand a good chance of rupturing something in your pulmonary system—like a lung. That's pulmonary barotrauma, and it can happen even a few feet from the surface.
More likely, however, is an accident that arises from feeling a little too comfortable with this easy-to-use system when, without it, you’d be less than competent underwater. You need to know how to clear a flooded mask, retrieve a regulator that has fallen from your mouth, shed your harness if necessary; and buddy-breathe if necessary. In short, you should have dive training. Everyone who used the Deck Snorkel at PS was a certified diver. (A couple of us got our tickets back when Jacques Cousteau lost his first flipper.)
Having said all that, and knowing that people will buy this rig without formal training, we can only emphasize the obvious: Be competent in the water in the first place, and remember to breathe. The Surface Dive website carries a link to online dive training at www.scuba-training.net. At least spend some time there familiarizing yourself with the basics.
We can highly recommend the Deck Snorkel, which can be ordered online. The basic one-person rig is $969, and comes with a 12-month warranty. It's not cheap, but it answers a lot of needs.
Contact - Surface Dive, 800/513-3950, www.surfacedive.com