NAUI standards require gas planning:
From NAUI S&P
2.29 -Monitor air supply and communicate amount remaining upon request and manage air supply so as to surface within a pre-planned minimum air limit.
2.30-Measure, record and calculate individual air consumption (as surface air consumption rate) using a submersible pressure gauge, depth gauge and timing device.
-Plan and make a no-required-decompression stop dive to a depth between 40 and 60 feet. Planning is to consider at a minimum: adequate breathing gas supply for descent, time at depth, ascent, precautionary stop and safety margin.