Being able to predict how long your gas supply lasts is an essential prerequisite for dive planning. I wrote a brief explainer for Alert Diver Magazine.

Everybody agrees that planning your gas reserves is an essential part of dive safety. At the same time, hardly anybody teaches it. That’s because it involves numbers and a bit of logical thinking – two things that recreational training agencies avoid like the plague. Instead, they’d rather talk about how snorkels come in different colors.

Now, some responsible instructors, including quite a few a know personally, go above and beyond and teach proper gas planning anyway, maybe in an AOW course or a Deep Diving specialty. However, if you want to take a class that actually requires systematic gas planning as part of its curriculum, you basically have to learn tec diving.

While I’m the last person to dissuade anyone from taking a tec diving class, I still don’t think that recreational divers deserve to be left in the dark like this. And if you want to know how I teach gas planning at the recreational level, then you can read my article in Alert Diver.