5 ms·

I can't verify this, but when the story broke in Germany there were some diving experts that claimed that you can dive there in those depths without decompressi

I can't verify this, but when the story broke in Germany there were some diving experts that claimed that you can dive there in those depths without decompression chambers and that people regularly do that. The entire discussion on what exactly you need to perform this operation has resulted in a whole bunch of contradictory opinions.

hotpotamus 4y ago
https://en.wikipedia.org/wiki/Shadow_Divers https://en.wikipedia.org/wiki/Shadow_Divers is probably worth a read if you have an interest. Basically it's about a group of hobbyist divers who explored a wreck at around that depth. They were definitely pushing the limits of amateur tech at the time, but I believe they also started using different gas mixes around then. What I don't understand is why divers would even be needed at all. Torpedoes and depth charges are hardly new tech. If you asked me to do it, I'd just find a commodity underwater ROV for the job and strap a big bomb to it. Problem solved. It's one of the asymmetries of warfare that it's a lot easier to destroy stuff than to build it.
- orbz 4y ago
  That’s probably a far more traceable operation using those approaches though.
EntrePrescott 4y ago
the need for decompression (and the required decompression time) is very much dependent on the duration of the dive (i.e. how much gas is dissolved into your blood depends on how much time your blood was fed gases at higher pressure). If your dive is just a quick down,drop some stuff, and back up right away (especially with a gas mixture optimized for depth)… then yeah, you might be able to do it without decompression… …whereas if you stay an hour or two down there, giving a long enough time for the gases to reach their high pressure solubility levels, you better not get back up without decompression.
lamontcg 4y ago
Open Circuit dive to 80m with 15 mins of working bottom time (CCR would cut total runtime down to 85 mins and slash the helium bill). I ran it with Nominal conservatism since I figure we're talking about people crazy enough to play around with explosives. You can likely cut off of half the O2 stop and as long as you pass your saving throwing against type I DCS and don't have a PFO you'll likely be fine for 4 dives. I would assume these people would wind up pushing the tables exceedingly hard. V-Planner 3.105 by R. Hemingway, VPM code by Erik C. Baker. Decompression model: VPM - B DIVE PLAN Surface interval = 5 day 0 hr 0 min. Elevation = 0m Conservatism = Nominal Dec to 80m (4) Trimix 15/55 18m/min descent. Level 80m 15:33 (20) Trimix 15/55 1.34 ppO2, 24m ead, 30m end Asc to 54m (23) Trimix 15/55 -8m/min ascent. Stop at 54m 0:45 (24) Trimix 15/55 0.95 ppO2, 14m ead, 19m end Stop at 51m 1:00 (25) Trimix 15/55 0.91 ppO2, 13m ead, 17m end Stop at 48m 1:00 (26) Trimix 15/55 0.86 ppO2, 12m ead, 16m end Stop at 45m 1:00 (27) Trimix 15/55 0.82 ppO2, 11m ead, 15m end Stop at 42m 1:00 (28) Trimix 15/55 0.78 ppO2, 10m ead, 13m end Stop at 39m 1:00 (29) Trimix 15/55 0.73 ppO2, 9m ead, 12m end Stop at 36m 2:00 (31) Trimix 15/55 0.69 ppO2, 7m ead, 11m end Stop at 33m 2:00 (33) Trimix 15/55 0.64 ppO2, 6m ead, 9m end Stop at 30m 3:00 (36) Trimix 15/55 0.60 ppO2, 5m ead, 8m end Stop at 27m 3:00 (39) Trimix 15/55 0.55 ppO2, 4m ead, 7m end Stop at 24m 4:00 (43) Trimix 15/55 0.51 ppO2, 3m ead, 5m end Stop at 21m 3:00 (46) Nitrox 50 1.54 ppO2, 10m ead Stop at 18m 3:00 (49) Nitrox 50 1.39 ppO2, 8m ead Stop at 15m 4:00 (53) Nitrox 50 1.24 ppO2, 6m ead Stop at 12m 5:00 (58) Nitrox 50 1.10 ppO2, 4m ead Stop at 9m 8:00 (66) Nitrox 50 0.95 ppO2, 2m ead Stop at 6m 10:00 (76) Oxygen 1.60 ppO2, 0m ead Stop at 3m 16:00 (92) Oxygen 1.30 ppO2, 0m ead Surface (92) Oxygen -6m/min ascent. Off gassing starts at 62.2m OTU's this dive: 110 CNS Total: 53.2% Gas density: 5.7g/l 183.8 cu ft Trimix 15/55 32.0 cu ft Nitrox 50 21.9 cu ft Oxygen 237.8 cu ft TOTAL DIVE PLAN COMPLETE ********* WARNING & DISCLAIMER ********* This V-Planner generated dive schedule could indirectly kill you. The author does not warrant that it accurately reflects the Varying Permeability Model algorithms, that it won't get you bent or dead, or that it will produce safe, reliable results. This dive schedule is experimental and you use it at your own risk. Diving in general is fraught with risk, and decompression diving adds significantly more risk. Deep diving utilizing multiple gasses, including Helium, is about as risky as it gets. This schedule is not intended for uneducated users. V-Planner and the decompression schedules it produces are tools for experienced mixed-gas decompression divers ONLY. If you have not been properly trained in mixed-gas decompression diving by an internationally recognized technical certification agency and/or don't have a firm handle on decompression planning and mixed-gas diving, then DO NOT USE THIS DIVE SCHEDULE.

hotpotamus 4y ago

https://en.wikipedia.org/wiki/Shadow_Divers https://en.wikipedia.org/wiki/Shadow_Divers is probably worth a read if you have an interest. Basically it's about a group of hobbyist divers who explored a wreck at around that depth. They were definitely pushing the limits of amateur tech at the time, but I believe they also started using different gas mixes around then. What I don't understand is why divers would even be needed at all. Torpedoes and depth charges are hardly new tech. If you asked me to do it, I'd just find a commodity underwater ROV for the job and strap a big bomb to it. Problem solved. It's one of the asymmetries of warfare that it's a lot easier to destroy stuff than to build it.

orbz 4y ago
That’s probably a far more traceable operation using those approaches though.

EntrePrescott 4y ago

the need for decompression (and the required decompression time) is very much dependent on the duration of the dive (i.e. how much gas is dissolved into your blood depends on how much time your blood was fed gases at higher pressure). If your dive is just a quick down,drop some stuff, and back up right away (especially with a gas mixture optimized for depth)… then yeah, you might be able to do it without decompression… …whereas if you stay an hour or two down there, giving a long enough time for the gases to reach their high pressure solubility levels, you better not get back up without decompression.

lamontcg 4y ago

Open Circuit dive to 80m with 15 mins of working bottom time (CCR would cut total runtime down to 85 mins and slash the helium bill). I ran it with Nominal conservatism since I figure we're talking about people crazy enough to play around with explosives. You can likely cut off of half the O2 stop and as long as you pass your saving throwing against type I DCS and don't have a PFO you'll likely be fine for 4 dives. I would assume these people would wind up pushing the tables exceedingly hard. V-Planner 3.105 by R. Hemingway, VPM code by Erik C. Baker. Decompression model: VPM - B DIVE PLAN Surface interval = 5 day 0 hr 0 min. Elevation = 0m Conservatism = Nominal Dec to 80m (4) Trimix 15/55 18m/min descent. Level 80m 15:33 (20) Trimix 15/55 1.34 ppO2, 24m ead, 30m end Asc to 54m (23) Trimix 15/55 -8m/min ascent. Stop at 54m 0:45 (24) Trimix 15/55 0.95 ppO2, 14m ead, 19m end Stop at 51m 1:00 (25) Trimix 15/55 0.91 ppO2, 13m ead, 17m end Stop at 48m 1:00 (26) Trimix 15/55 0.86 ppO2, 12m ead, 16m end Stop at 45m 1:00 (27) Trimix 15/55 0.82 ppO2, 11m ead, 15m end Stop at 42m 1:00 (28) Trimix 15/55 0.78 ppO2, 10m ead, 13m end Stop at 39m 1:00 (29) Trimix 15/55 0.73 ppO2, 9m ead, 12m end Stop at 36m 2:00 (31) Trimix 15/55 0.69 ppO2, 7m ead, 11m end Stop at 33m 2:00 (33) Trimix 15/55 0.64 ppO2, 6m ead, 9m end Stop at 30m 3:00 (36) Trimix 15/55 0.60 ppO2, 5m ead, 8m end Stop at 27m 3:00 (39) Trimix 15/55 0.55 ppO2, 4m ead, 7m end Stop at 24m 4:00 (43) Trimix 15/55 0.51 ppO2, 3m ead, 5m end Stop at 21m 3:00 (46) Nitrox 50 1.54 ppO2, 10m ead Stop at 18m 3:00 (49) Nitrox 50 1.39 ppO2, 8m ead Stop at 15m 4:00 (53) Nitrox 50 1.24 ppO2, 6m ead Stop at 12m 5:00 (58) Nitrox 50 1.10 ppO2, 4m ead Stop at 9m 8:00 (66) Nitrox 50 0.95 ppO2, 2m ead Stop at 6m 10:00 (76) Oxygen 1.60 ppO2, 0m ead Stop at 3m 16:00 (92) Oxygen 1.30 ppO2, 0m ead Surface (92) Oxygen -6m/min ascent. Off gassing starts at 62.2m OTU's this dive: 110 CNS Total: 53.2% Gas density: 5.7g/l 183.8 cu ft Trimix 15/55 32.0 cu ft Nitrox 50 21.9 cu ft Oxygen 237.8 cu ft TOTAL DIVE PLAN COMPLETE ********* WARNING & DISCLAIMER ********* This V-Planner generated dive schedule could indirectly kill you. The author does not warrant that it accurately reflects the Varying Permeability Model algorithms, that it won't get you bent or dead, or that it will produce safe, reliable results. This dive schedule is experimental and you use it at your own risk. Diving in general is fraught with risk, and decompression diving adds significantly more risk. Deep diving utilizing multiple gasses, including Helium, is about as risky as it gets. This schedule is not intended for uneducated users. V-Planner and the decompression schedules it produces are tools for experienced mixed-gas decompression divers ONLY. If you have not been properly trained in mixed-gas decompression diving by an internationally recognized technical certification agency and/or don't have a firm handle on decompression planning and mixed-gas diving, then DO NOT USE THIS DIVE SCHEDULE.