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Maggie’s Motivational Pic Thread v2.0 - - New Rules - See Post #1

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Well, according to some research, divers did reach at least 155 meters (511.5 ft). Quite an accomplishment, given the deepest "pinacle" cave dive in Florida is "Diepolder II."

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The "Grand Ballroom" you see here is at 270ft at the bottom. But it goes deeper than that (to 365ft.). I don't know how many people are able to get to the deeper portions because time at this depth is extremely limited (9 minutes at most) before you have to start back up and start your decompression schedule. And this is with you being on 10-70 Trimix for Bottom gas. You'll have 2-3 different gas switches enroute and upon return. It takes years to work up to this dive, even after trimix training.
I ran a 165" pipeline inspection boat in the GOM in the mid '70's. Three decompression chambers, 15 man dive team breathing Oxygen, inspecting oil and gas pipelines, live boat, walking divers down the pipeline as deep as they could go.. They got "Depth Pay", you can figure it out.
The mantra was "The Lord lives at 188". Most all those guys have found max depth and found it early in life.
 
Mix for a possible 500 foot OC dive like the Cetina River Spring in Croatia? It wouldn’t be one, it would be several. Like five or more depending on your profile. If someone was crazy enough to do it, It would probably just be a bounce dive with 10 minutes to get down and 201 minutes to come up. Maybe 10/70, 21/35, 35/25, EAN50, and then 100% O2. That would get you to 495 at 1.6 but if profile holds at 1.4, things change. In other words, if you want to see whats on the bottom, rent an ROV you’ll live longer.
 
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Mix for a possible 500 foot OC dive like the Cetina River Spring in Croatia? It wouldn’t be one, it would be several. Like five or more depending on your profile. If someone was crazy enough to do it, It would probably just be a bounce dive with 10 minutes to get down and 201 minutes to come up. Maybe 10/70, 21/35, 35/25, EAN50, and then 100% O2. That would get you to 495 at 1.6 but if profile holds at 1.4, things change. In other words, if you want to see whats on the bottom, rent an ROV you’ll live longer.

Yeah, I don't think I've ever heard of a mix with an FO2 lower than 10%. If there is, it's not being taught in any curriculum by TDI or the Cave diving agencies. It would have to be something done privately by the dive teams.
 
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Well, according to some research, divers did reach at least 155 meters (511.5 ft). Quite an accomplishment, given the deepest "pinacle" cave dive in Florida is "Diepolder II."


The "Grand Ballroom" you see here is at 270ft at the bottom. But it goes deeper than that (to 365ft.). I don't know how many people are able to get to the deeper portions because time at this depth is extremely limited (9 minutes at most) before you have to start back up and start your decompression schedule. And this is with you being on 10-70 Trimix for Bottom gas. You'll have 2-3 different gas switches enroute and upon return. It takes years to work up to this dive, even after trimix training.

Well, according to some research, divers did reach at least 155 meters (511.5 ft). Quite an accomplishment, given the deepest "pinacle" cave dive in Florida is "Diepolder II."


The "Grand Ballroom" you see here is at 270ft at the bottom. But it goes deeper than that (to 365ft.). I don't know how many people are able to get to the deeper portions because time at this depth is extremely limited (9 minutes at most) before you have to start back up and start your decompression schedule. And this is with you being on 10-70 Trimix for Bottom gas. You'll have 2-3 different gas switches enroute and upon return. It takes years to work up to this dive, even after trimix training.
Sheck did it on air.

With rebreathers, there are more people willing to try this dive, but still not a lot of people who actually belong there.
 
Yes, we cave divers do "stage" tanks but IME, most of it is more "horizontal distance" oriented than depth. FTR, I'm ANDP and Full Cave. Not yet Trimix certified but I have had practice planning said dives, including DII. But most of those types of dives do not involve depths below 200 ft and require only basic Trimix (18-35), not "Advanced" (10-70). Only a few select cave divers with the most experience get to do dives like Eagle's Nest and the Diepolders. And, yes, they do stage for depth on those becuse there isn't much in the way of "horizonal distance" to go on them. Just "vertical."

Just to see what would happen, I actually planned a DII dive on VPlanner, given my own parameters, etc. I allowed for a 50% O2 stage tank at 70ft. 100% O2 at 20ft (no lower), and the bulk of my "back gas" was 18-35 with a switch at 218ft to 10-70 for bottom gas. Even with that, VPlanner didn't want me "at depth" for more than 9-10 minutes before having to return to start the deco schedule. Maybe it (and I) were being conservative, but I'd rather err on the side of "conservative" (in more contexts than that, these days...) :ROFLMAO:

I understand about rebreathers and how they are supposed to work. Have they resolved the CO2 issues with them? That (and the cost) is what kept me away from them. And having to have a "bail out plan" for them anyway just made me say, "Why bother?" I"ll stick with the proven technology of open circuit. That, and the fact that I've lost personal friends who perished due to rebreather issues. Not going there.

Perhaps, there are divers who can extend bottom time much longer. I suspect they'd have to be more physically fit and experienced such that their gas consumption at depth is minimized. Certainly more than I'll ever be. Like I said, DII is a "pinacle" dive for me. Perhaps. a "Holy Grail" dive (one I'll never get to) given my age, especially sicne I've yet to take my Trimix training. But I guess if we achieve all our goals, we'd get bored quickly.

Some things need to be left "unfinished."
Sorry if I came off as challenging you, or claiming super diver status, not intended or true. I'm am a trimix diver, although not much of a cave diver I am advanced wreck so some similarities with penetration. A local dive I have done many times takes me to about 250ish so I am also not a novice. My total dive time on these run about 80-100 min and yes my bottom time is short.

I'm not suggesting to dive beyond ability or comfort zone, but V-planner is conservative. More I was trying to show in the article what is possible. There are better gases than trimix and divers are going way beyond 270ft now. That was a crazy depth when I started diving back in 1987, but not now.

Happy to hear from other tech divers, it was a great chapter in my life. Most of my diving these past years is with my wife who does not tech dive, but I still have to go deep now and then when I get the itch.
 
Yeah, I don't think I've ever heard of a mix with an FO2 lower than 10%. If there is, it's not being taught in any curriculum by TDI or the Cave diving agencies. It would have to be something done privately by the dive teams.
I did several multi day trips to deep wrecks where we could only bring 2 sets of doubles and 2 deco tanks. We had a compressor and 2 k's of O2 on the boat, so we started on the deepest wreck and kept blowing our doubles back with air. I started those trips with 8/92 heliox. The deepest wreck was around 280, so didn't need that mix for the depth, but it let me have decent mixes on the subsequent wrecks.

When commercial guys were doing sat dives to 800+ feet, they used mixes with even less O2.
 
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