AIR 2 OR NOT TO AIR 2.

To hear the perceived benefits, and of course drawbacks, of each, just bring half a dozen divers together. The debate will wage unabated for hours. Why'd they do that? Depending upon their original training and subsequent diving experience, opinions of appropriate scuba gear are deeply ingrained early in one's diving career. Let's compare some of the options.

The most common alternate air source for recreational divers is the octopus unit. An alternate second stage mounted on a low pressure hose slightly longer than your primary mouthpiece to facilitate sharing air should your buddy run low. Depend ing upon the year you were trained, the octopus either hangs upside down for you so that it is easier for your buddy to use, or right-side up to also be of service to you. Yes, training conventions do change over time. Advantages to an octopus unit include it's ease of use in shallow water, at depth, and it is a relatively inexpensive accessory. Disadvantages include some divers allowing it to drag behind them causing this emergency tool to be full of sand and inoperable or hard to find, or both. Also the concern that this is not an additional source of air has merit. Divers sharing an already depleted source of air part way through a dive may both end up "breathless". Regular servicing and use of an octopus "holder" can solve most of these disadvantages. Several manufactured holders are available or a little creativity can ensure this second stage is tucked in, easily accessible and functional.

Losing the extra hose and providing the diver with a more streamlined profile was a major factor in developing products such as Scuba Pro's Air 2 and Sherwood's Shadow. These miniature second stages integrated into the low pressure inflator hose of the buoyancy compensator solved the diver's concern of where to find their alternate air source. It's always hanging in front of you. With every solution however comes compromise. With these systems the diver gives up their main regulator to their buddy to share air while they, being more calm and controlled, used the alternate source. Great in theory but there are some divers out there who did not enjoy giving up their easy-to-breath regulator to a buddy who then seemed to crawl all over their shoulder during the ascent. Seemed to be? Have you ever tried to control your buoyancy and watch your buddy while you had your head tucked into your armpit? It's not easy. At depth, some of these earlier units provided significant breathing resistance similar to sucking Jell-O through a straw. Newer units made of advanced materials with improved breathing mechanics have overcome this issues.

Another option is Spare Air. This affordable mini-tank complete with it's own regulator fits onto the waistband of the diver's BC. Redundant air in a compact format that could be handed to anyone in need of an extra breath or two. No problem, right? Well there are a few cautions even with this system that divers need to be aware of prior to diving. It does only carry a few breaths which obviously become fewer as depth increases. Divers who have dived with the regulator in the "on" position, to ensure it was ready for use, have discovered it empty when needed or tested. Divers passing it off to a buddy unfamiliar with the need to open the valve before trying to breath have witnessed a few rushed emergency swimming ascents often followed by a string of verbal abuse from said buddy. Care also needs to be taken to carry the filling adapter especially when traveling out-of-country or you may wind up with an empty spare piece of baggage.

The return of many divers to pony bottles and double tanks starts looking like the best option for truly having alternate air. You are carrying a little or a lot depending upon the size of the tank. It is user friendly for you or your buddy and all you had to do was carry an extra tank around underwater, on the surface, buy an extra regulator, purchase another pressure gauge, buy a mounting bracket for the extra tank, and determine how to keep all this extra gear from dangling in your way now that there appears to be two of most everything. As attractive as it seems, this is not an option selected by most divers.

Other options may come to mind for your alternate air needs while you read this. Good. Each diver needs to examine the conditions under which they divewarm water vs. cold, shallow vs. deep, air vs. mixed gas, and so on. Backup systems are important and necessary to your diving safety. Many dive stores will allow customers to try out different systems either in controlled settings or during courses. Select the one that suits your diving needs and your budget. Then practice with it. Then you too will be amused when you hear, "Octopus." "Air 2." "Octopus." ...