A Question for submatix owners

[NARKEDAT30]

This question is placed on here for information and feedback,it is directed to Submatix MCCR owners. I went to Swanage with the unit this weekend. Dive 1 on Sunday morning on Kyarra 32mts planned. The unit pre-breathed ok and the ADV operation was checked.Entry into the water was over the gunnell and I chose to do a straddle rather than a back roll.Due to short slack times skipper advised us to enter water early with a some tide still running. Had to work quite hard to reach the bouyed descent line. Also had to pull myself down the line. As descent progressed my breathing became restricted and I was begining to breath the loop down to below minimum volume...the ADV did not operate. Bailed out at 24mtrs when breathing became rapid and shallow. After 4 or 5 breaths on bailout normal breathing pattern restored. Back on the boat I had a look at the unit and the OPV was 1 click from closed. Somewhere from me preparing the unit that morning in the van and tranferring to the boat or possible on entry,the OPV had been knocked closed.Other than that there was nothing 'wrong' with the unit.Subsequent 2nd dive on the Betsy Anne at 25mtrs that afternoon and no problems. I would like to conduct a straw poll and ask users to let me know what setting they use for their OPV. Please answer by the number of clicks from closed that you set your OPV. I would like to establish what 'others' have been told in 'training' Regards Narkedat30.

[Nick Kay]

Hi Narked at 30

Hold on... the ADV doesn't have an adjust!?

The only problems I've had with the ADV have been when one of the head-weights "disconnected" and lodged one of the counterlungs

With regards to the auto-purge, I tend to close mine fully when doing the pos/neg checks and then open up 5 clicks - I don't know whether the setting on this has any eggect on the ADV?

I also try and run the loop at MLV whenever possible

Must admit I prefer straddle or giant stride entries to backward rolls

Regards

Nick

[steveharriss]

I don't have a submatix but from your description you are referring to the OPV rather than the ADV. These should have no effect on each other..at least they don't on a Meg and I can't see your unit being any different. I leave my OPV closed unless doing dil flushes or on ascent, when I fully open it. Or am I misunderstanding?

[Nick Kay]

Originally Posted by steveharriss

I don't have a submatix but from your description you are referring to the OPV rather than the ADV. These should have no effect on each other..at least they don't on a Meg and I can't see your unit being any different. I leave my OPV closed unless doing dil flushes or on ascent, when I fully open it. Or am I misunderstanding?

My brain died when I posted the 1st reply:
- obviously I meant "OPV" rather than "auto-purge" (but then I am getting on a bit)
- I think to adjust the OPV on the Sub you'd either need to be triple-jointed or a gorilla (or both)

I believe (under certain conditions) there were some problems with the exhale lung failing to re-fill after someone took a huge breath - this was fixed by shoving a curly-wurly in the lung!

[steveharriss]

Ah..I see. Forgot the counter lungs on the submatix aren't OTS.

[sexydivebuddy]

narked, i think you mean the OPV. as nick said, the ADV doesn't "click".

my OPV is shut when doing pos and neg checks but i open it 15 "clicks" for the dive. also, as nick said, very difficult to operate the OPV ourselves.

as a matter of interest, was the OPV secured properly in the case prior to the dive and / or could it have become "unseated" upon entering the water and therefore got somehow "jammed" inside the case?

[Luddite]

I have mine set at 12 clicks but it is the SCR model so I need it the hight to dump the air that is always bleeding into the loop. I hope to be going MCCR over the christmas period so I'll have to play around with it then.

[NARKEDAT30]

Thanks for the input so far people but keep it coming please. Yes your quite correct I had a blonde moment .....I was referring to the OPV setting..........but...........the ADV is adjustable.....by 'bending' the leaf spring inside the valve....but thats another story.More examples please on your chosen OPV setting in relation to the number of clicks from closed.The OPV was seated correctly.

[sexydivebuddy]

probably typing rubbish but was it possible that due to the hard physical effort at the beginning of the dive, you somehow "out-breathed / over-breathed" the unit [hyperventilation] and had a CO2 hit / build-up which got exacerbated with depth?
doubt if it was scrubber channeling as all was ok for the second dive.

my manual says 0-10 clicks. i know a couple of divers who dive their OPVs fully closed quite happily. it was trial and error for me re number of clicks until i was comfy.

[sallyw]

I close mine to do the negative and positve test but I always have a bit of a battle to ensure that it is clicked securely into the unit. I always have mine open on 5 clicks while I dive the only time I ever notice it playing a role is as I ascend and I tend to do a few hard breaths out at various intervals as I ascend to get the OPV to kick in and reduce the loop volume.
I know my other half dives with it closed all the time and he prefers it that way.

I know that we also never roll in backwards wearing the units even if it means an undignified climb over the gunwales. Not quite sure why - I just do as I am told

Sally