Understood, but the post was about multilevel diving where some significant portion of the dive is spent at shallower levels, potentially less than 50'. And, you agree that you need to know the residual N2 for repetive diving.
lamont:Time spent shallow will primarily impact slow compartments which have long NDLs. As long as you're not doing a lot of repetitive multi-day diving (e.g. liveaboards) those will not be controlling compartments. The faster compartments have higher m-values and are already probably loaded up to the partial pressure of that depth. If you just came up from a 100 fsw dive for 30 mins on EAN32, what is happening to your slower tissues at 50 fsw isn't going to start affecting your NDL for awhile, and unless you're taking a nap there, the "bottom time" and "ongassing" time of the dive can be assumed to be over -- you can hang out at 50 fsw and when you start to ascend the real issue is still decompressing those faster compartments which were loaded up at 100 fsw. The stop at 50 fsw made some slower compartments more loaded, and it shifted your controlling compartment slightly slower, but unless you've stayed there so long that you're running up against your NDL at 50 fsw the problem is still those faster compartments. Clearly you're still ongassing into slow compartments, but they aren't going to be important until you start planning your next dive and figuring residual nitrogen in slower tissues left after your SI...