Diver one of sixteen to die using high-tech gear

[john j]

If you want a fair comparison of OC to CCR deco times, you have to use the same gases in each case to gauge the deco advantages of CCR. If I I did a dive on a CCR using the same gases you just did, the total deco time would be 31 minutes compared to your 41 minutes for OC. In addition, I would have never exposed myself to a 1.6PO2 like you did. (V-planner table shown below). Considering how cold the water is in Superior, I'd be very pleased with a 10 minute reduction in deco time, which by the way makes the dive safer in some aspects than OC. That comes out to almost 25% less deco time on this dive on CCR comapared to OC.

Another huge advantage is that with one fill of my CCR and bailout bottles, I could repeat this dive about 4 or 5 times without ever having to switch tanks or get any fills. That's a huge benefit in my practice. Furthermore, if I decided to do a shallower dive during the trip, I still would have optimized PO2 whereas you would not with the mixes you proposed. CCR's are extremely flexible.

Surface interval = 1 day 0 hr 0 min.
Altitude = 0ft
Conservatism = Nominal

Dec to 200ft   (4) on Diluent 18.0/45.0, 0.70 SetPoint, 50ft/min decent.
Level 200ft 16:00 (20) on Diluent 18.0/45.0, 1.30 SetPoint, 76ft END
Asc to 130ft   (21) on Diluent 18.0/45.0, 1.30 SetPoint, -60ft/min ascent.
Stop at 130ft 0:50 (22) on Diluent 18.0/45.0, 1.30 SetPoint, 43ft END
Stop at 120ft 1:00 (23) on Diluent 18.0/45.0, 1.30 SetPoint, 38ft END
Stop at 110ft 1:00 (24) on Diluent 18.0/45.0, 1.30 SetPoint, 34ft END
Stop at 100ft 1:00 (25) on Diluent 18.0/45.0, 1.30 SetPoint, 19ft END
Stop at 90ft 1:00 (26) on Diluent 18.0/45.0, 1.30 SetPoint, 15ft END
Stop at 80ft 2:00 (28) on Diluent 18.0/45.0, 1.30 SetPoint, 11ft END
Level 70ft 1:00 (29) on Diluent 50.0, 1.30 SetPoint, 44ft END
Asc to 60ft   (29) on Diluent 50.0, 1.30 SetPoint, -30ft/min ascent.
Stop at 60ft 1:40 (31) on Diluent 50.0, 1.30 SetPoint, 36ft END
Stop at 50ft 2:00 (33) on Diluent 50.0, 1.30 SetPoint, 29ft END
Stop at 40ft 3:00 (36) on Diluent 50.0, 1.30 SetPoint, 21ft END
Stop at 30ft 3:00 (39) on Diluent 50.0, 1.30 SetPoint, 14ft END
Level 20ft 1:00 (40) on Oxygen, 1.40 SetPoint, 0ft END
Stop at 20ft 4:00 (44) on Oxygen, 1.40 SetPoint, 0ft END
Stop at 10ft 7:00 (51) on Oxygen, 1.32 (1.40), 0ft END
Asc to sfc.   (51) on Oxygen, -30ft/min ascent.

NOTE - This Multi Level dive requires intermediate deco stops between levels.

OTU's this dive: 73
CNS Total: 27.7%