Quote:
| Originally Posted by Brian of Aquanauts Going through my TDI Instructor manual all I can find for deco gas requirements is "Cylinder volume appropriate for planned dive and student gas consumption". So TDI leave this to the instructor, do IANTD recommend your reserve amount? |
IANTD recommends 1.5 for back gas (thirds) and 1.2 for the decompression bottle generally. As per the encyclopedia(soon to be replaced), although this is STRESSED that this is the absolute minimum amount required. I usually get people to plan their dives using a significantly higher RMV this way you will have some more gas than you need unless you triple your SAC, especially if people diving dissimilar sized cylinders with SAC. Although this still might not be enough.
A good starting point a rough max RMV, is getting them to swim against each other for 5 mins (at 6m) and noting the amount of gas they use. Then working out their RMV from that data. But they only get out of it what they put in
