Drmike

I think everyone is missing the main advantage of a BOV.

Having a bov promotes an earlier bail. which I believe is a big safety feature

I found when diving without a BOV the percieved hassle of bailing to OC (closing dsv, spitting it out, locating and fumbling for offboard 2nd stage reg and shoving it in me gob) the large stress raiser of having to come off the loop, was enough to encourage me to delay bailing until I was VERY sure I was having a problem. My thought process was , 'I dont want to go to the hassle of bailing unless I am very sure Im having an issue ...so lets wait a fe moments longer and see if I start feeling worse'.

With a BOV and the easy turn handle bail I found that it encouraged me to bail at the slightest feeling that something wasnt right. Bailing with a BOV is far far less of a stress raiser also which can be a critical thing during CO2/Stress/panic scenario when your trying to reduce your rmv. In addition bailing with a BOV in a way doenst feel like your coming off the loop in a way as teh dsv stays in your mouth. Changing the status quo in my experience is a major stress raiser during stressful times (one reason why it can be impossible to even come off the loop if it requires you to 1) stop breathing 2) spit out your dsv. With a BOV it feels significantly less like anything has changed and you dont have to pause breathing. (the latter point IMHO is absolutely critical to appreciate)

The longer one delays to bail the higher up the CO2 spiral ride to death we are and the harder it is to recover - and if high enough we cant recover (and likely cant even bail)

This is why I even preffer the side reg on the nova over a BOV (I dont use BOV with the nova) because with the side reg Its even easier to bail (get fresh gas) just by nose breathing - the end result is that I automatically and habitually start nose breathing whenever I feel almost impercievable levels of CO2

basically:
Side reg = fastest encouraged bail* at earliest possible sign, no stress raiser
BOV = early encouraged bail, min stress raiser
OC = slowest encouraged bail, highest stress raiser, risk of flooding loop,


*with the side reg I wouldnt even call it a bail as its more a prevention rather than a cure.

Most BOV dont breathe well so I would consider them only as a 1st step on OC bail. I would only have it plumbed into 1st deep bail tank then when ready to switch gases should be perfectly calm enough by then to come off the bov and go to offboard 2nd stages.
IMO gas switchblocks are stupidly dangerous and the risks dont outweigh the benefits

__________________
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