Current Views on Hypoxic bailout/BOV Configurations

[Whitrzac]

Starting MOD3 soon and looking for opinions on how everyone else handles hypoxic bailouts with a BOV. Or if nothing's changed in the past 10+ years and everyone does what they want anyway, lol

Kiss classic, stiffer spring/orifiace. Onboard o2/dil with drysuit bottle.

 

[nadwidny]

I don't understand why the question. Your hypoxic bailout is for the deep part of the dive. Your RB craps out, switch to your BOV. Congratulations. You are now an OC tech diver. As you come up you will be on OC and switching gases just like every other OC tech diver. Your hypoxic bailout doesn't come into play.

 

[Alaskan Scuba Dude]

BOV or DSV?

 

[KenGordon]

Starting MOD3 soon and looking for opinions on how everyone else handles hypoxic bailouts with a BOV. Or if nothing's changed in the past 10+ years and everyone does what they want anyway, lol

Kiss classic, stiffer spring/orifiace. Onboard o2/dil with drysuit bottle.

If you look at the numbers and see how hypoxic your bailout has to be to be a problem at a shallow stop I think you will find it is unlikely for anything but a mix like 8/ something. In the unlikely circumstances you are using that (and your MOD3 ticket will only be 100m so you’ll be on your own education wise) then try to remember to bailout directly to the proper mix. You’d need to be properly top of your game and likely with hours of boredom on such a dive so if that gas swap (Ie bailing out shallow direct to a regulator) is a challenge do not go there.

 

[JonG1]

A friend who has just done his mod 3 said his instructor who used a bov basically plugged in the correct bailout for the depth during the ascent/descent.

He was using a dsv and completed bottle rotations to keep the correct dil in place up front on the descent/ascent.

Following on from Kens comments for me the riskiest area is surface, on way in or out, especially on entry if something were to fail on the rb during entry, if your bov is plugged to deep tin

 

[KenGordon]

said his instructor who used a bov basically plugged in the correct bailout for the depth during the ascent/descent.

This scares me. All the extra complication of switch blocks or whatever to manage the gas routing seems like a way to properly get it wrong.

By way of illustration, I considered adding an extra bailout feed from my onboard dil reg so I could jump 8m to shallow (like 10-15m) lakes without the hassle of a 7. On reflection I thought the risk of me accidentally plugging my BOV into that rather than the offboard feed was non zero so didn’t do it.

My view is that the BOV is to make the initial switch off the loop as easy as possible, especially for a CO2 hit. Once you are getting to 40m say and due to switch then you should be past the acute problem and have the time, space and brain power to switch to a conventional regulator.

I have dived with people with madly complicated setups which aim to solve a large number of unlikely scenarios, it justs ends up impossible to explain and so impossible for me to diagnose or help with in the water.

 

[Peter10/50]

I used a BOV for a couple of hundred hours but switched to a DSV when I started using hypoxic bailout gases.

I fiddled with complicated plumbing but never became adept at plugging and replugging the qc6. It seemed to me that liklyhood of being either on the wrong gas or not plugged in at all while near the surface was all too common.

 

[PfcAJ]

I just accept that I can’t breath from the BOV for long when shallow and git on with it.

 

[JonG1]

I used a BOV for a couple of hundred hours but switched to a DSV when I started using hypoxic bailout gases.

I fiddled with complicated plumbing but never became adept at plugging and replugging the qc6. It seemed to me that liklyhood of being either on the wrong gas or not plugged in at all while near the surface was all too common.

So how do you configure your bailouts, do you bottle rotate, so that a breathable gas is always available in each depth segment?

 

[Vicko]

Even a 8/60 or something similarly hypoxic is kind of breathable at 20 meters, so it is a viable bandaid until you sort your problem out. And to be realistic if you need something that hypoxic to bail out than you have more than enough time on your shallow stops to make sure you switch your bailout gasses to something more appropriate for that depth.