Joshua Smith wrote:600'? For the love of god, Greg, really? Did you have support? Safety divers? WTF were you testing? Why did it need to be tested that deep? And, yeah, what was your BO plan?
That was as I said a equipment test off Monterey last year. Testing new electronics for a military unit. It was a staged dive off a boat in open water with full safety crew and chamber on board. The next test is to 1200'. I took the rEvo along to see how it faired and to show the unit to the DARPA team. Even though it does not have the legs the test unit has it worked great. The only problem was Paul did not get me the radial scrubbers in time for the dive. So I used the Axial and ran 6hrs on them before bailing off the unit to the hat. I had never ran longer than 5 hrs on the axial before. Do not know if I was taking a CO2 hit or if was just anxiety of being on it so long or the work of breathing was crap by that point or a combination. I can say that was the first time booth scrubbers were purple and I had to use a screwdriver to chisel the sorb out.
I did also screw a few things up on the dive. The faceplate's of my dreams got cracked around the bolt heads from the defection and I flooded one of them a few weeks later the crack made it past the o-ring. I also screwed up the Piazo button on my Shearwater. I never understood why the buttons got so hard to press after that until Bruce told me if you drop too fast it will do that to Piazo's. The stage drooped at 100'/min to 400' then stoped for 2 min for gas changes and stabilization then 100'/min to 600'. I never let off the dill button and never hit the upper wall all the way down. I was worried about having to flag for a stop and screwing up the test data but I kept up.
Finally getting them replaced with the Predator upgrade and depth sensor upgrade as we speak Curt is fixing all that.
Josh I am keeping 6/70 banked now for dives to 500 all the time now and have bailouts made for it sitting in storage ready to go any time.
On Bailout Expedition diving is just like expedition climbing at some point the rope has to come off. Group bailout is the only way you can really venture much below 300'. Just as with the San Clemente destroy at 270' we all did group bailout. 2 man teams carried a 80 of 15/35 and a 80 of 60%, Three man teams carried a 80 of 15/35 and a 40 of 60%, We also had a 80 of 100% on the line at 20' and safety diver carrying spare 80's should someone need it.
This was the baiout plan for the 3 man group on the San Clemente Destroyer.
Dec to 200ft (2) Diluent 10/50 0.70 SetPoint, 80ft/min descent.
Dec to 270ft (3) Diluent 10/50 0.70 SetPoint, 80ft/min descent.
Level 270ft 16:38 (20) Diluent 10/50 1.30 SetPoint, 114ft ead, 125ft end
Asc to 190ft (22) Trimix 15/35 -30ft/min ascent.
Stop at 190ft 0:20 (23) Trimix 15/35 1.01 ppO2, 108ft ead, 112ft end
Stop at 180ft 1:00 (24) Trimix 15/35 0.97 ppO2, 102ft ead, 105ft end
Stop at 170ft 1:00 (25) Trimix 15/35 0.92 ppO2, 95ft ead, 99ft end
Stop at 160ft 1:00 (26) Trimix 15/35 0.88 ppO2, 89ft ead, 92ft end
Stop at 150ft 1:00 (27) Trimix 15/35 0.83 ppO2, 83ft ead, 86ft end
Stop at 140ft 1:00 (28) Trimix 15/35 0.79 ppO2, 76ft ead, 79ft end
Stop at 130ft 1:00 (29) Trimix 15/35 0.74 ppO2, 70ft ead, 73ft end
Stop at 120ft 1:00 (30) Trimix 15/35 0.69 ppO2, 64ft ead, 66ft end
Stop at 110ft 2:00 (32) Trimix 15/35 0.65 ppO2, 57ft ead, 60ft end
Stop at 100ft 2:00 (34) Trimix 15/35 0.60 ppO2, 51ft ead, 53ft end
Stop at 90ft 3:00 (37) Trimix 15/35 0.56 ppO2, 45ft ead, 47ft end
Stop at 80ft 4:00 (41) Trimix 15/35 0.51 ppO2, 38ft ead, 40ft end
Stop at 70ft 5:00 (46) Trimix 15/35 0.47 ppO2, 32ft ead, 34ft end
Stop at 60ft 6:00 (52) Trimix 15/35 0.42 ppO2, 26ft ead, 27ft end
Stop at 50ft 4:00 (56) Nitrox 60 1.51 ppO2, 9ft ead
Stop at 40ft 5:00 (61) Nitrox 60 1.33 ppO2, 4ft ead
Stop at 30ft 8:00 (69) Nitrox 60 1.14 ppO2, 0ft ead
Stop at 20ft 34:00 (103) Nitrox 60 0.96 ppO2, 0ft ead
Surface (103) Nitrox 60 -30ft/min ascent.
Off gassing starts at 199.2ft
OTU's this dive: 94
CNS Total: 34.7%
96.4 cu ft Trimix 15/35 -
we have 240 cu ft
63.8 cu ft Nitrox 60 -
we have 120 cu ft
160.2 cu ft OC TOTAL
The O2 is their if we need it but is not planed in the dives unless needed. All it will do is get you out of the water a few minutes faster but really adds to the CNS and OTU clock. So if you do not need it don't use it.
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Here is baiout plan for a 15min @ 500' 3 man group.
Dec to 200ft (2) Diluent 6/70 0.70 SetPoint, 80ft/min descent.
Dec to 500ft (6) Diluent 6/70 0.70 SetPoint, 80ft/min descent.
Level 500ft 8:45 (15) Diluent 6/70 1.30 SetPoint, 126ft ead, 135ft end
Asc to 400ft (18) Trimix 7/70 -30ft/min ascent.
Stop at 400ft 0:40 (19) Trimix 7/70 0.92 ppO2, 93ft ead, 97ft end
Stop at 390ft 1:00 (20) Trimix 7/70 0.90 ppO2, 90ft ead, 94ft end
Stop at 380ft 1:00 (21) Trimix 7/70 0.87 ppO2, 87ft ead, 91ft end
Stop at 370ft 1:00 (22) Trimix 7/70 0.85 ppO2, 84ft ead, 88ft end
Stop at 360ft 1:00 (23) Trimix 7/70 0.83 ppO2, 81ft ead, 85ft end
Stop at 350ft 1:00 (24) Trimix 7/70 0.81 ppO2, 78ft ead, 82ft end
Stop at 340ft 1:00 (25) Trimix 7/70 0.79 ppO2, 76ft ead, 79ft end
Stop at 330ft 1:00 (26) Trimix 7/70 0.77 ppO2, 73ft ead, 76ft end
Stop at 320ft 1:00 (27) Trimix 7/70 0.75 ppO2, 70ft ead, 73ft end
Stop at 310ft 1:00 (28) Trimix 7/70 0.73 ppO2, 67ft ead, 70ft end
Stop at 300ft 1:00 (29) Trimix 7/70 0.71 ppO2, 64ft ead, 67ft end
Stop at 290ft 1:00 (30) Trimix 7/70 0.68 ppO2, 61ft ead, 64ft end
Stop at 280ft 1:00 (31) Trimix 7/70 0.66 ppO2, 58ft ead, 61ft end
Stop at 270ft 1:00 (32) Trimix 7/70 0.64 ppO2, 55ft ead, 58ft end
Stop at 260ft 2:00 (34) Trimix 7/70 0.62 ppO2, 52ft ead, 55ft end
Stop at 250ft 1:00 (35) Trimix 7/70 0.60 ppO2, 49ft ead, 52ft end
Stop at 240ft 2:00 (37) Trimix 7/70 0.58 ppO2, 46ft ead, 49ft end
Stop at 230ft 3:00 (40) Trimix 7/70 0.56 ppO2, 44ft ead, 46ft end
Stop at 220ft 1:00 (41) Trimix 20/40 1.53 ppO2, 95ft ead, 119ft end
Stop at 210ft 1:00 (42) Trimix 20/40 1.47 ppO2, 90ft ead, 113ft end
Stop at 200ft 2:00 (44) Trimix 20/40 1.41 ppO2, 85ft ead, 107ft end
Stop at 190ft 2:00 (46) Trimix 20/40 1.35 ppO2, 80ft ead, 101ft end
Stop at 180ft 1:00 (47) Trimix 20/40 1.29 ppO2, 75ft ead, 95ft end
Stop at 170ft 2:00 (49) Trimix 20/40 1.23 ppO2, 70ft ead, 89ft end
Stop at 160ft 3:00 (52) Trimix 20/40 1.17 ppO2, 65ft ead, 83ft end
Stop at 150ft 3:00 (55) Trimix 20/40 1.11 ppO2, 60ft ead, 77ft end
Stop at 140ft 3:00 (58) Trimix 20/40 1.05 ppO2, 55ft ead, 71ft end
Stop at 130ft 3:00 (61) Trimix 20/40 0.99 ppO2, 49ft ead, 65ft end
Stop at 120ft 5:00 (66) Trimix 20/40 0.93 ppO2, 44ft ead, 59ft end
Stop at 110ft 5:00 (71) Trimix 20/40 0.87 ppO2, 39ft ead, 53ft end
Stop at 100ft 6:00 (77) Trimix 20/40 0.80 ppO2, 34ft ead, 47ft end
Stop at 90ft 8:00 (85) Trimix 20/40 0.74 ppO2, 29ft ead, 41ft end
Stop at 80ft 10:00 (95) Trimix 20/40 0.68 ppO2, 24ft ead, 35ft end
Stop at 70ft 6:00 (101) Nitrox 50 1.56 ppO2, 32ft ead
Stop at 60ft 9:00 (110) Nitrox 50 1.41 ppO2, 26ft ead
Stop at 50ft 10:00 (120) Nitrox 50 1.26 ppO2, 20ft ead
Stop at 40ft 16:00 (136) Nitrox 50 1.10 ppO2, 13ft ead
Stop at 30ft 21:00 (157) Nitrox 50 0.95 ppO2, 7ft ead
Stop at 20ft 14:00 (171) Nitrox 50 0.80 ppO2, 1ft ead
Stop at 15ft 75:00 (246) Nitrox 50 0.73 ppO2, 0ft ead
Surface (246) Nitrox 50 -30ft/min ascent.
Off gassing starts at 427.4ft
OTU's this dive: 204
CNS Total: 76.0%
189.2 cu ft Trimix 7/70
180.7 cu ft Trimix 20/40
193.1 cu ft Nitrox 50
563 cu ft OC TOTAL
With surface supplied 100% if needed. You would stage the upper gasses or this can be done live carring 4 80's each with group baiout. And that is not all that bad to carry but it is much easier to carry 2 80's and stage the rest.
If carring you have
320 cu ft Trimix 7/70
320 cu ft Trimix 20/40
320 cu ft Nitrox 50
960 cu ft OC TOTAL