Bailout?

[beanie]

what bailout to people carry?
gases / cylinders
and at what depths ie different bailout options for different depths?

just thinking of options

[Foggy]

[KISSer]

Gases - something you can breathe (or are prepared to breathe) at your max depth for long enough to get your sh!t together, plus whatever deco gas combination means you can get out in reasonable time with reasonable safety.

Sizes - just work out how much gas volume you need to deco out at the end of your planned bottom time using your chosen mixes (above) and go from there. Some people carry all their own bailout, some rely on drop tanks from a support boat, some split the bailout with their buddy assuming they aren't gonna have that bad a day, some dive alpinist and some just haven't worked it out yet.

The contrary argument is that most rebreather failures are detectable early in the dive and so you don't need bailout for your full bottom time, but tell that to the KISS diver who reportedly punctured a hose after something like 25min at 60m.

ie. it all depends on what diving you're doing, who you're doing it with (buddies and boats) and how pessimistic you want to be.

[wreckweasel]

Originally Posted by beanie

what bailout to people carry?
gases / cylinders
and at what depths ie different bailout options for different depths?

just thinking of options

Beanie, we did this one to death a while back... search the archive fella

/Z

[Pierre Farrugia]

Hello just came from a 60m 25min bt OC dive, and me and my buddy were discussing about bail out once we have our rebreathers and are good enough on them to do these dives (which will take more than a year...I know), but here OC experience helps. Today we used 100bar from a 10L cylinder, so if it was a RB dive, I would have needed a 5l tank, At this point we have 100 bar reserve! So I think to have our emergancy covered a 7L, for these dives or little bit deeper should be enough, altough every one's RMV should be considered!

Regards

Pierre

[PrettyFishies]

Long standing debate this one. I am currently using inboard and outboard diluent and O2. With the right amount of regs and buttons on the lungs, this means I can breathe all the gases I carry, both open and closed circuit or semi closed. I have 2 O2 buttons and 2 diluent buttons on the lungs. Each button has a separate gas plugged in and all my hoses are interchangeable (you can buy the hose pipe and connectors and custom make your own hoses).

I do not use the yellow shell or black box that the unit comes in, it's all mounted on a stainless steel frame, allowing multiple gas configurations to be deployed very quickly and easily. This means that I can mitigate every failure mode (for deeper stuff bigger bottles can be mounted on for extra bailout) as well as keeping all the inboard and outboard gas connections to the lungs.

One thing to consider is that most people carry sidemount bailouts however do not have redundancy against O2 loss of gas, i.e. from an o-ring or first stage blow out on the oxygen side. This could be fatal. It is worth giving consideration to mounting a little 1.5 litre offboard O2 bottle with an interchangeable hose that can be plumbed into the lung in the event of the primary O2 source failing.

If you want to see a pic of the jan box with all the different gases plumbed in please email me on am23uk@yahoo.co.uk

[And]

Originally Posted by AnneMarie

If you want to see a pic of the jan box with all the different gases plumbed in please email me on am23uk@yahoo.co.uk

Or look here

http://www.therebreathersite.nl/jan_box.htm

Andy

[Narked@50]

3L pony with air when diving singles and nothing if I'm on twins. Bail out should be exactly that, some people carry 36% nitrox in their ponies, but unless your going to empty it for deeper dives it could be wastfull or inconvienient as a bailout.

James

[Drmike]

As I hopefully never have to use my bail-out gas (touch wood) I just keep two tanks filled with gas all year around (or at least until I do a practice drill). Typically an 11L filled with 18/20 and a 7L filled with 50-70%.

I do the dive with the 11L plugged into my FFM OC mouthpiece and being 18% its breathable at any depth. When (bailing) I get to the gas switch I just unplug and plug in the 70%

95% of my dives are sub 50m so I'm on trimix. It makes sense to bail to a weak trimix as I want to be sharp if some problem has led me to have to bail deep inside a wreck. I don't mind if I bail to a high PO2 momentarily as I will most likely be ascending quite soon after bailing so the PO2 will be dropping.


I dont consider the on board 3L when planning Bailout due to the fact they are so small and usually only contain 100bar at the dive start.

I can plug both bailout tanks into my RB if needed.

Usually with the dives I'm doing an 11L and 7L is not enough to finish all deco on but the idea is to have enough OC gas to get back to the line and up to the deco platform where theres surface supplied O2, OR if I missed the line and doing a free floating deco I have enough gas to get up to 6m and start my long hang whilst I wait out the surface crew to bring me a drop tank with more O2 (yellow SMB deployed to indicate gas needed)


If the dive requires more bail out gas (longer, deeper or usually due to a longer penetration) then I will stage an 11L on the wreck near the line containing a higher FO2 to speed up deco. The 11L I carry is normally enough to get me to that point.

I carry both bail tanks with me during the whole dive in case I need to bail and for some reason cant get back to the line.

On a big wreck or in bad viz I drop the 7L if doing a penetration only when its 100% guaranteed I will be exiting where I entered (it hardly ever is so I usually carry) plus on one dive deep inside a wreck I lost my whole on-board O2 in about 10 secs, so its good to have some high FO2 to run the RB manually with.

All bail tanks have a whip that can be plugged into my FFM.


This has worked well for me (so far) but I'm always looking for better ways of doing things.

I dont like to dive unless I know I am fully self sufficient and carrying all my life support supplies. Even when diving in a buddy pair or team I still carrying all my bailout myself.

[Fij-Iain]

I used to do it similar to Ammers but have changed recently. Used to back mount everything, have the ability to plug it all in etc but found that it was just too much weight for me on my back - my centre of gravity shifted way too far back for my liking !!!!

I have mounted my bailout cylinders side mount style so they are nicely out of the way, using same sort of gases as Drmike. I have tossed around the idea of a small O2 cylinder but when I did my "risk assessment" decided that it wasn't worth it - I'm not doing dives that require 2 or more hours deco. If I was I'd probably look to a twinspiration cause it is just plain silly carrying all that OC stuff ... :-)