In technical diving, gas planning is critical. Unlike recreational dives, most technical dives don’t allow direct access to the surface. If anything goes sideways during the dive, you must deal with it on the bottom.
Your best asset when dealing with problems is time, which means having sufficient gas available to keep breathing long enough to solve the problem. SAC stands for “Surface Air Consumption.” It applied to all scuba diving breathing gasses, not just air. Sometimes, you’ll see the term, RMV (Respiratory Minute Volume) used to mean the same thing. They’re not the same thing, but close enough that either is fine.
Your SAC Rate is the rate in cubic feet (for this SAC calculator anyway) that you consume a given breathing gas. It is adjusted to the volume of gas you’d consume at the surface. That way, the calculation is useful for dives to any depth.
I’ll get into details later, or in some future article.
This is the best SAC rate calculator on the Internet. I wrote it as a plugin, which I think is pretty cool. What’s different about this SAC Calculator is I have accounted for any gas you use to inflate your drysuit, and/or the gas you use in your BCD or wing.
I also account for altitude, fresh vs. salt water and some other factors. Check it out!
