By John Kinsella
What hasn’t been said about air consumption? It’s one of the first questions non-divers ask. (How many times have you answered the infamous “How long does your oxygen last, mister” question?) It’s a nearly mandatory post-dive topic thereafter. There are many articles written on the subject. There are thousands of blogs, vlogs and calculators devoted to it. If you delve into air consumption theory and calculations, things quickly start to get a bit complex. If you look at the subject from both a metric and imperial point of view, even the way fundamental baseline measurements are made change. It’s enough to make the less mathematically inclined run for cover.
But leaving all that aside, there’s one easy thing an instructor I know does to help his student divers reduce their air consumption. He simply keeps a spreadsheet with the start and finish air pressure for every student on every dive (He also tracks names, contact info, training dives, certs and so on). With a simple formula, he can track an individual diver’s air consumption in bar (he works in a metric region) over the course of all their training dives. Admittedly, there are tons of details this approach ignores (in particular cylinder capacity) but in a way that’s the whole point. Helping divers manage their air consumption doesn’t have to be complex.
More than anything, it’s the simple act of asking divers for the information that prompts the insightful post-dive conversations. The spreadsheet is readily accessible on the instructor’s mobile device. A quick comparison of a diver’s current to previous air consumption provides a talking point: “I see you used a lot less air on this dive, why do you think that’s the case?” The discussions lead to opportunities to explain some of the finer details and methods for more advanced gas management strategies (and this in turn is a great way to promote related Con Ed such as Enriched Air Diver, Sidemount, Tec and Rebreather courses).
As the old adage goes, you can’t manage what you don’t measure. Here’s a simple, interesting and effective way to help divers do both.
Do you use any other methods to help your divers manage their air consumption? Share in the comments.