Doing AN/DP with FFM, Realistic?

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cruisekingkris

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I have to believe there are people doing OC tech dives with a FFM. I've been diving a FFM for 12 years and have tried most of the recreational brands out there. I'm Currently using the OTS stealth. Now I want to take it up a notch with the AN/DP TDI course but I do so much diving on my FFM that if I couldn't figure a way how to Deco dive it, I wont take the course. I feel like I seen people mention it on SB but cant find any posts.

In my head, I think the use of the FFM would be for the decent, bottom time and ascent until the first gas swap. Finishing the dive on what I think would be my long hose with secondary reg. Is there a configuration that is preferred for this or am I SOL. I'm not looking to be part of any certain "Group" I dive what is safe and works for me and my buddy.

I appreciate the overall experience of the divers on this site. I'm not looking for the "ffm are dumb" or "why do you need to do that" remarks. Just wondering if there are any like masked divers out there to offer up options. Trying to find out information from SB before I bother a TDI instructor for possibly no reason.
 
Just out of curiosity, why would you need to switch from your ffm to a conventional kit even on the first gas swap? I'm no tech diver (yet) but I'm kinda in the same boat you are. Primarily a ffm diver and want to do AN/DP soon so I'm definitely interested to see what you find out. But even for your gas swap, couldn't you just have a QD fitting on the hose and swap that way rather than having to doff your ffm and don a conventional mask and 2nd? I know the OTS is a bit different setup than my Oceanreef but couldn't you still install a QD between the primary hose and 2nd stage reg? That would essentially eliminate the need for you to ever doff your ffm unless there was an issue with the mask itself. Just my thoughts and certainly something I can bring up to our TDI tech instructor next time I see him.
 
IF you're going to do it, IMO you need to do it with a switch block. Planning to do decompression on the half mask is counterproductive since that's where most of the time is going to be spent.
No reason in TDI standards that you couldn't do it, though any prudent instructor would certainly have you do at least one dive just on the half mask, and then have you do gas switches with both the switch block and switch to the half mask.

Now whether they'll do it, I don't know. I wouldn't have an objection to teaching it, but as I don't have the desire to do those kind of dives, nor the experience doing them, I would be hesitant. I would contact Chatterton as he'd be someone more likely to have experience doing those kind of dives and be able to tailor a course to you.

Other option is just take the AN/DP course in a half mask, and then figure it out how you're going to adapt that to the FFM.
 
I'm not sure about the OTS, but I know the ocean reef FFM's are capable of being connected to two gas sources. Combine that with a quick disconnect and you could do all your gas switches while still on a FFM. It's not super complicated and is one of the intended uses for the second input port on an FFM. The other being a redundant first stage/gas supply I guess. I'd guess you would have to find a FFM friendly instructor to take an AN/DP course in FFM.

In my experience though, I had to take tech courses in "standard" configuration. Then later switch to a special config such as FFM.
 
I'm not sure about the OTS, but I know the ocean reef FFM's are capable of being connected to two gas sources. Combine that with a quick disconnect and you could do all your gas switches while still on a FFM. It's not super complicated and is one of the intended uses for the second input port on an FFM. The other being a redundant first stage/gas supply I guess. I'd guess you would have to find a FFM friendly instructor to take an AN/DP course in FFM.

In my experience though, I had to take tech courses in "standard" configuration. Then later switch to a special config such as FFM.
I suppose with the Oceanreef you could utilize the SAV port with the octo adapter to connect a second gas source then just turn one bottle off and the other on to switch gases. Might be a bit crude but functional.
 
I suppose with the Oceanreef you could utilize the SAV port with the octo adapter to connect a second gas source then just turn one bottle off and the other on to switch gases. Might be a bit crude but functional.
Put something like this behind the QD
61efKASwWHL._SL1500_.jpg

I guess I am thinking more than two gasses. I've never taken AN but my assumption was that you'd get into more than two.
 
"Every time we sell a manifold or switch block, we shudder a little bit. The gas switch block is used in primarily by surface supply divers to switch from surface supply to emergency bailout gas. Manifolds are primarily used in gas distribution systems. But the key here is that there are not different gas mixtures involved. Unfortunately divers sometimes get the idea to match these products up with multiple cylinders and/or or quick disconnects to create some type of elaborate system for rapid switching between different gas mixtures and/or cylinders. Gas switching errors are very often involved in technical diving accidents. Over the years we've learned about several near misses and fatalities that were directly attributable to mistakes with switch blocks that were connected to different gas mixtures. No matter how careful the diver, or how many safeguards, we think using switch blocks with different mixtures is a very bad idea."


Manifolds and Switch Blocks | Dive Gear Express®
 
I see you having 2 options.
Option A
Complete AD/DP in conventional set up and gain experience enough to see how to adapt a FFM into your procedures including team based actions.

Option B
Find a very flexible TDI instructor that has experience with switch blocks/QC 6's and piece together the program. As an aside this could be done easier in sidemount configuration with a manifold and QC 6's. There is an agency that supports this in its public safety diver training syllabus.

I very much concur with Ken, the introduction of complexity can only be mitigated by proper training and repetition to the point of total muscle memory.....and even then.....
 
I agree. The idea of using a manifold or switch scares me. Too easy to select the wrong gas on purpose or by accident and too hard for your buddy to verify your gas selection.

There would have to be a really compelling need for me to go this route. At a minimum, I would devote a lot of thought to how I went about it so that it is a deliberate multistep process that fails "safe."
 
https://www.shearwater.com/products/perdix-ai/
http://cavediveflorida.com/Rum_House.htm

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