Nitrox? Why the heck would anyone want to dive Nitrox for? Trimix is where it's at. All the advantages of Nitrox without all the narcosis.
I'd like to see the schedule for the poor sod trying to deco on a 18/40 mix.. Would be spending some time on the 3 meter stop...
EDIT: And here's the schedule for that dive done with 18/40, 55 and 100, and lost gas scenarios to illustrate
-- lost gas -->
OK 55 100 Both
78 (12) (12) (12) (12)
48 0 (16)
42 1 (17) 1 (17)
36 1 (17) 1 (18) 1 (17) 1 (18)
33 1 (18) 1 (19) 1 (18) 1 (19)
30 1 (19) 1 (20) 1 (19) 1 (20)
27 1 (20) 1 (21) 2 (21) 2 (22)
24 2 (22) 2 (23) 1 (22) 2 (24)
21 2 (24) 2 (25) 3 (25) 2 (26)
18 4 (28) 3 (28) 4 (29) 3 (29)
15 4 (32) 4 (33)
12 1 (30) 5 (37) 1 (31) 6 (39)
9 3 (33) 8 (45) 3 (34) 8 (47)
6 4 (37) 5 (50) 6 (40) 12 (59)
3 7 (44) 8 (58) 9 (49) 24 (83)
E