Choptima MAV -> ADV

[boriss]

Hello fellow divers,

I've been trained to dive my Choptima with an MAV and have had no issues so far -- I actually like the manual control and find it works well for maintaining minimum loop volume.

Currently, I'm diving with a wetsuit, so my buoyancy management is relatively simple: just loop and wing. However, I'm considering switching to a drysuit, and that introduces an extra buoyancy device to manage. This has me wondering whether it might make sense to switch over to using the ADV, at least initially.

The ADV on the Choptima has an inline shutoff, so in theory I could keep it active for descent and then shut it off at depth to prevent unwanted injections. But I'm not sure how realistic that concern is -- is this a common issue? Would it be smart to start practicing with the ADV now, even while still using my wetsuit, so I’m comfortable with it before adding the drysuit?

I'm all for maintaining full manual control when it's appropriate, but I’m also trying to be mindful of task loading and not adding too many new variables at once. I’d really appreciate any thoughts or experiences others might have -- especially from divers who made similar transitions.

Thanks in advance!

 

[lostsheep]

I took the adv off my chop as soon as they released the mav and don't miss it one bit. I was diving with the slider off all the time anyways to prevent unwanted additions. I basically always dive drysuit and usually with a dpv. It IS a lot of task loading but you'll get used to it fairly quickly.

My .02psi is to keep diving it the way you are familiar with; if you are just learning drysuit, get dives in without the rebreather until you get comfy with the drysuit. Combine the two after each is second nature.

YMMV

 

[boriss]

I took the adv off my chop as soon as they released the mav and don't miss it one bit. I was diving with the slider off all the time anyways to prevent unwanted additions. I basically always dive drysuit and usually with a dpv. It IS a lot of task loading but you'll get used to it fairly quickly.

My .02psi is to keep diving it the way you are familiar with; if you are just learning drysuit, get dives in without the rebreather until you get comfy with the drysuit. Combine the two after each is second nature.

YMMV

Thanks for your response! For reference, what type of diving do you do? My biggest concern is in a hot-drop situation, which is every technical dive here.

 

[lostsheep]

Thanks for your response! For reference, what type of diving do you do? My biggest concern is in a hot-drop situation, which is every technical dive here.

Mostly shore dives with dpv, occasional boat but hot drops are rare. I wouldn't think twice about hot dropping with drysuit and mav; managing the 3 volumes has turned into second nature.

 

[LFMarm]

I was trained with ADV and was keeping it open only for the descent. I decided to transition to MAV because (1) the ADV is less sturdy and (2) opening the shutoff to enable the ADV is more cumbersome than just MAV.

On (1): I ended up fracturing the ring that holds the ADV when using stages that eventually bang on it. This caused flooding the unit.

When diving with MAV and dry suit, there is a lot going on with buoyancy but I now have developed a quick movement with right hand managing all.

 

[stretchthepenn]

I haven't tried to wrangle the dil MAV on a hot drop, but I'm on Team MAV for the same reasons as the other commenters.

As @LFMarm noted, the ADV isn't as sturdy as the MAV; during my training, the ADV disintegrated because it'd been factory-tightened too much.

As @lostsheep wrote, I usually kept the slider off. In theory, the ADV's ability to regulate loop volume is neato, but theory doesn't match practice; I only used the ADV on descent, and when it fired, the additions were typically annoying, unwelcome, or both. Plus, the on/off slider was cumbersome. I spent more time fumbling for the damn thing than I did with the slider in the ON position.

 

[Mobulai]

Team MAV!

I already plan to blank the ADV on the SW that I’m yet to buy (ok it’s crap anyways)

I’ll admit, the ADV came in clutch on ne dive — just one, my 3rd training dive
When I forget to open my right cylinder; and started sucking on the CL and got nothing, a very quick slap in the face to remember to REALLY check everything before thumbing down, quitely opened the valve, swallowed my shame, my instructor and teammate none the wiser (till we got out)

Otherwise the ADV is a pain — it kept messing about with the min loop volume and adding more than I needed (I still breathe with OC “glutton”)

 

[Rollin Bonz]

I’ll admit, the ADV came in clutch on ne dive — just one, my 3rd training dive
When I forget to open my right cylinder; and started sucking on the CL and got nothing, "

This is true BUT when this happens because you forgot to open the inline valve (obviously doesn't help if you forget to open your tank valve), it's soooooooo much easier to press the button on a MAV than it is to fumble with (and just as likely DISCONNECT the damn dil hose instead of opening) the inline valve on the ADV.

Trained with the ADV (off except for descent)
Dove it for 2 years with the ADV.
Made the switch to MAV last fall.

Team MAV

 

[makar0n]

My 3 cents:
So far diving with ADV and loving it. I find it very comfy when either going down, or say suddenly dropping a few meters because I saw a nudibranch riding mantis shrimp while singing Ride of the Valkyries, and the loop gets tad spicy but not yet bad enough to warrant a full flush.
In both cases I can just deal with this using my cake hole - inline valve stays open though. Task loading and hands free wise it is quite comfy, especially with a Nerd combination and having that pO2 in yer face.

Key was to tune the ADV down - it was too sensitive out of the box. So it won't trigger with just normal breathing, but needs a deeper suction action to activate. In fact I might even try to further desensitize it and see how that goes.
Reliability wise, no issues at all.

It was recently a bit annoying on one dive, where I did blow through waaay too much dil - but then that was the day I was under the weather with a lovely cold, and my breathing was all over the place. So perhaps then MAV could be better? Dunno, cannot really blame ADV too much, if I was not sick, there would be no issue really. Well at least dive shop was happy, since it was a 90m, that helium turned out to be darn expensive

 

[grantctobin]

Thanks for your response! For reference, what type of diving do you do? My biggest concern is in a hot-drop situation, which is every technical dive here.

Gotta add gas to your suit right? Hand is already needing to do things so might as well let it add MAV gas too. Worst case, you can start with a slightly higher than optimal loop volume when you hop but all in all, the hot drop difficulties are kind of overblown.