Drmike

Hmmm, When I experimented with having both sets of hoses coming from same side I found the hoses (when pressurised and therefore stiff) did make head movement to that side harder.



The issuse with some QCs is more the limiting flow rate through them. Your adding a QC, shut off valve, Y manifold and swivel between you and your gas supply - best to minimise pressure losses where possible when your facing high RMV at depth, which is why my QC is only for side reg - real bail is direct form off board 2nd stages with no elbows, qcs or flow stops =KISS


Personally I dont see need for BOV if you have a side reg (or visa versa) I dont see that as KISS. To me one of the major benefits of the side reg is you can continue to breathe during gas switching. - With your configuration you wont be able to do that as your side reg and bov are fed from same supply

For you a gas switch will go something like this:

1) Find your next bail tanks QC, pull out hose..hold it in your right hand
2) Turn off current offboard bail tank valve with your left hand?
3) Breathe few more breaths from current offboard tank until pressure = zero*
4) Hold breath and fumble to disconnect QC (which takes 2 hands so you drop the new QC from your right hand)
5) Still holding breath try to relocate dropped new QC and then connect new QC (Fumble fumble fumble., why wont it connect?..fumble fumble, connect will you!, fumble fumble - need to breathe!, fumble fumble, getting stressed, fumble, fumble need to breathe, getting more stressed, wont connect! Oh shit!! [been there done that ]


At this point your only opition (unless you have p-port adapted 2nd stages on bail tank) is to violently rip off your full face mask and whilst recovering from shock of cold water on face and loss of vision adding even more stress to an already stressful situiation you struggle to find your bail gas 2nd stage and turn valve on. ..ahh a good day out




In contrast my bail goes like this;

1) Begin nose breathing from side reg.
2) fumble for p-ported 2nd stage (take as long as you want because your side reg is plumbed into same bail tank)
3) casually, at your leasure, insert 2nd stage into front p-port opening
4) stop nose breathing and start mouth breathing


And for me it will be the same at each subseqent gas switch

KISS


There are many reasons why a QC can be hard to connect underwater:

(issues Ive had with APD and Swagelock)

1) Dirt gets into female QC (APD/S)
2) Connecting pin gets damaged/bent (S)
3) Internal failure - seal extrudes preventing operation (APD)
4) Forgot to depressurize 2nd stage side of QC (APD,S)
5) Crud inside QC (APD)

Add stress of needing to breathe to the mix and any of the above (or just clumsiness in lining up QC) can lead to a need-to-breathe panic


Bottom line to me is I see a disconnected QC as an additional barrier between me and my bail gas. its an unecessary barrier (as you have 2nd stages on your bail tanks) it gives no real advantage (other than percieved comfort advantage of staying on bov....) but adds considerable risk if it fails to connect quickly enough or at all as it could means you cant breathe (without first ripping off your ffm) and if that wasnt enough reason, adding qcs to all bail tanks adds failiure points, considerable cost and chances are high that your bov doesnt even breathe as well as your offboard 2nd stages anyway


So personally I would sell the BOV, put p-port adapters on your offboard 2nd stages (with mouthbites pulled over them for non ffm buddies) and KISS. Indeed I would rather only have the 1st deep bail tank 2md stage fitted with a p-port adapter and plan on bailing off the ffm to back up normal mask at next gas switch then add compexity and failure points of a bov and heap of qcs....but thats just me Each to his own






*
2 and 3 best done because:

1) In case of QC stuck open failure in which case you will loose heaps of gas at depth, gas that your life may still depend on if your bail calcs are wrong [lesson learnt hard way]
2) Most QCs are impossible to re-connect if 2nd stage side is still pressurised!! (see one cause of 5 above), another lesson learnt the hard way

__________________
Cave diving is a sport
Wreck diving is a sport
Diving in general is a sport

'Rebreather diving' is not a sport
its the delusional obsession with a highly dangerous and often inappropriate piece of equipment