Bailout, too much of a good thing?

[SoggyFox]

been thinking through some bailout strategies and having spent a weekend with a couple of guys on a boat with different thoughts on bailout. What do you do in planning your bailout and then diving it?

do you plan your bailout to come out clean from any deco obligation with something left over, including an elevated SAC to start with at the early stages of bailing out.

do you know how much gas you have in your bailout tins and accept that there is a chance that while you'll make the surface, you've probably missed stops and will need observing when your back on the boat.

or do you ascend like a homesick angel and hope for the best.

i think this is relevant for both recreational CCR and trimix CCR, i use a 7lt with 28% on most wrecks down to 40ish but beyond that its a couple of 11lt with a deep mix and 80%, might be over kill with the 11's at the moment but in the long term it appears a rational choice to me. I know down to 40m it may be touch and go if the 7 will at times fully cover any deco i've racked up but i accept that i should be able to make the surface and get help but going deeper i tend to think that having more than enough and some left over just in case is the way to go. I know its contradictory but i feel i can accept the risk.

your thoughts and general slagging of my approach welcome.

[hebails]

not yet made the (inevitable for me at least) leap to CCR yet but I can't see how having too much gas on a bailout can be a bad thing. If you can comfortably dive with both stages then why not use them on the deeper stuff.
Cheers
Paul

[NotDeadYet]

I like to over-spec my bailout. I've bailed out due to CO2 a couple of times, it wasn't fun and even with a shitload of gas around me, in my head there wasn't going to be anywhere near enough which unsettled me which made me breathe harder, etc... vicious circle. The first time it happened I have never felt so close to losing it underwater as I did then for the first 5-6min on OC. CO2 scares me a lot more than anything else does.

I work on 25l/min for the first few minutes of deep bailout, which is around double my SAC. I'm not convinced that's enough for a major CO2 incident though. If I'm caving then I take a "sacrificial" bottle equivalent in size to my deepest bailout. In open water I'm a bit more liberal but my minimum deep bottle is still an ally 80, I've also got ally 12.2's which I've used as well (an extra 6-700litres of wind).

For deco I plan on 15l/min which is a bit closer to my SAC as by that time I'd hope I'd be calm and there would be other divers around anyway. In the deco plan I usually include a table for being able to go back on the loop at 6m. I plan for completing all my deco.

Planning dives... I work out what the loop will be at depth and plan the dive as OC, using the bailout gas(es). When I get a plan that works within the gas margins then I go back and work out a CCR plan for the same bottom time. I do the opposite when I'm caving, plan what bottom time I want then chuck bailout at it as needed. If you need half a dozen bottles then that's fine because you can drop them where needed before the main dive.

Shallow dives... bailout is easy. I dive a twinset On most dives I can get away with just backgas or a small deco stage, with a rebreather then I still need to carry something big enough to cope with CO2.

Cheers,

Stuart

[Rob Dobson]

Whenever possible I use team bailout; knowing that if I was to lose the team and the loop I have enough gas to get up and do reasonable deco but not necessarily come out clean.

Bailout remains a key issue for me and I'm still looking to move to a fully redundant CCR.

[Bottle Maker]

If I am shallow (less than 30) I carry a single 7 with some sort of nitrox mix in it, down to 50 a seven with 20/30 and a seven with 50%
Deeper than 50 an 80 good for the depth and either a seven or another 80 with 50% in it and a drop bottle of 80 on the boat.
I carry 50% as I can get on it a lot deeper than 80%

I worked my bale out at an average of sac of 30 that will only just get me to 21meters.
I have 80% in the drop bottle as that is what it came filled with and I have not used it although 100% may be better as I could plug that into the unit if its the ellectrics that are dead or lost my inbourd O2.

I do not have a lot of deep experience on CCR so welcome the coments of more experienced divers.

Graham.

[nigelH]

I haven't got to the full alpinest position of no bailout yet but I can see the attraction of it. Clambering about with enormous stages of gas that go from one hydro/visual to the next untouched is beginning to get a bit wearing.

The trouble is that I'm a coward...

[Reikimaster]

Originally Posted by nigelH

The trouble is that I'm a coward...

but at least you are hear to say that

[nigelH]

Originally Posted by Reikimaster

but at least you are hear to say that

But I'd still be here if I had never carried bailout.

This is the problem. When does carrying tens of kilos of extra kit on every dive actually sum up to being less safe than not taking it? Do we need more inventive ways round the very few 'dead loop' situations.

[NotDeadYet]

Originally Posted by nigelH

This is the problem. When does carrying tens of kilos of extra kit on every dive actually sum up to being less safe than not taking it?

When you need it?

Do we need more inventive ways round the very few 'dead loop' situations.

Absolutely.

[Steve Jones]

I have a 7 litre of trimix for my deep bail out mixed to 18/40

My other bail out is also a 7 litre with 50% nitrox.

I also have a 7 litre drop cylinder on the boat, again it is 50% nitrox.

The above set up is what I would use to about 75 metres, deeper than that and I would switch the 7 litre bottom bail out to an aluminium 80 cylinder, with appropriate gas mix for the depth (PO2 of 1.6 approx, and enough helium to give an END of 40 metres)

Steve