More bailout please....

Timbo

Just a thought, why get bigger cylinders. If you have double buttons on the counter lungs, then you can plumb in off boards and semi-close the unit, two side-mounted 7's will last forever this way,

Ah yes you may say but then my PO2 will drop and my deco schedule will go through the roof.

Well if you are on a vision electronic set up you can monitor PO2, or if you have a fourth cell linked to a VR3 likewise. Obviously deco is longer, but in the shallows you can then get on OC, if you want.

For Tri-Mix dives up to 80M i carry a 15/40 dil inboard, or a 16/40.

Offboard 7 is 18/35 and a 50% ( two 7's )

I can also breath my inboard both dil and pure 02 via o/c, and i carry a 3 litre bolted to unit with air for suit inflation, which still has a reg on.
Therefore i have 23 litres of o/c gas to either breath o/c or semi-close.
Plus my buddy does the same, so in effect if my unit goes t**ts up we have 46 litres of oc gas between us. PS in 6 years on my Inspiration i have never had to get off the loop. ( Now i have said it i will be bailing out next week!!!!)

Also there are tables avilable to take into account semi-closed operation that allow for a purge rate of 1-3 or 1-5.
The mob i Tri-Mix with only carry 3's on their rebreathers. However coz i am chicken i carry 7's

Just a suggestion if you dont like it please ignore my waffle.
Tim B

Janos

Or put 30% Helium in them. Ok, not great for your last bottle, but fine for a bottom bailout.

Janos

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Digger

A vote for the 80s here. Partly becasue I've got a couple and don't want to seem like the only one, but also I got them for good reason.

Mine run at 210 bar. They're not heavy in the water with that amount of gas in them, I've not found many steel tanks which I find bearable at that pressure. Fresh water it's worse, sea water either will probably do. I've seen Mark's Fabers float same way my 80s do when empty in the sea, but less so.

I find the length is good for me, sits by my side, whereas when I used shorter tanks they sit in front of my legs and can interfere with my divine finstrokes

The way it is with ally 7s in the UK you could sell them and buy a couple of 80s probably, I'm assuming you're going to keep them for shallower stuff though.

You're very welcome to use my pair for a dive or two to try out. I've got a couple of 60s now which are just lovely for mid-range stuff. Mmmm...

Out of the water I can't say I've had any problems with them. They're not that heavy, but then I don't walk far with them on. As for bulk, the tail of the tank just sits behind me, no great shakes. You know what I'm like for carrying shed-loads of bailout, I wouldn't carry 2 for shallow dives if it was a pain in the arse.

Digs.

PS -Tim, what do you do in the event of major leak/flood? Torn hose for example? Semi-closed isn't always an option. Diving wrecks around the UK I've caught things up several times, so far not a breathing hose, but I don't doubt it's possible, especially on rummage dives or low viz. On 2 3litre tanks OC you probably wouldn't even make the surface on deeper dives, on 7s you'd get out bent, it just doesn't work out in my head. But then, it's the old alpinist debate really...

Timbo

Digger,
Exactly if you get a flood on just 3's you are in the kaka. ( thats why i carry 7's)
Hence the sevens, if with my buddy then 4 X 7's

If you lose buddy, well probably out bent. although we always go back to shot, so should be someone else with gas.

If that fails then i think with so many things gone wrong ho hum!!!!

I do not think you can plan for absolutely every risk ( although i will be shot at on this forum for saying that ). You may as well say i want 6 O2 sensors in case the first 4 go wrong!!

But also how many people have had total loop faliure

i can only go from experience of regularly diving with 15 different Rebreather divers, and no-one has had one in 6 years. We may just be lucky, i bet there will be a flood (ho ho ) of people saying they have had loop faliure. Still each 2 their own. As i always say "If it works 4 you and you are happy it must be okay"
Thats all, keep em peeled
Tim B

nmanfield

Agreed,

One of the things to consider is also the possibility of Inwater recompression. There have been some excellent studies on this but there has to be a weighing up of - howe bad is the bend, how cold is the water, how bad the tide, is there someone to monitor what I'm doing, Have i got a FFM, how close is the chamber (one thing I saw - are there hungry tigersharks in this location and should I therefore go somewhere else!) can an alternative locatioon be found etc etc etc.

Mark Ellyatt has put it far more eloquantly than I - some great artilcles on this website: http://www.inspired-training.com/Inwaterreco.htm

Regards

Nick

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Digger

But you don't need IWR if you carry bailout sufficient to get out ok.

Tim, I must have misunderstood, but thought most of your team were carrying 3s and you 7s. In that case you might be ok with a small deco obligation, but they probably wouldn't be, unless you were around to provide gas. That said, I'd be a bit pissed with someone who I had to pull out of dodge because they didn't carry enough bailout (to a point, obviously).

Each to their own, but SC whilst ascending isn't a viable way out of dodge for me. Too complicated and there's easier ways of doing things IMO. That said, I don't pretend to understand everything there is to understand, but for my dives there is always a way out OC, even if that includes team bailout.

Digs.

Timbo

Digs, If i may call you Digs!!
It is half and half really, 50% are on 4X3litre cylinders, eg two in the unit and two backmounted.
The other half use 7's.

The half that use 3's work on the principle that a bubble check at 6M should show up leaks, or it becomes obvious on the way down or as soon as you get to bottom of the shot. That way they have 2 lots of 4X3L's to get up.

However me being sooper cautious use two 7's side slung with a 3 of air for suit inflation plus access to my inboard 3's, so does my regular buddy. So me and him are alright in a complete loop flood with all deco to do.
Obviously if we both get a loop flood, well then it is going to be tight. But thats the day i will stop doing the lottery!!!!
Equally if we got separated and then had a flood, we may have to accept a minor bend.

IMPORTANT
We run a system where we have a drop gas on the boat, all the team carry yellow delayed marker bouys. The skipper knows if this comes up then he clips a bottle and reg to your line on a bouy and lowers it down.
We tend to take a couple of 7's with 50% and 80% in on expeditions.
We know it works coz we tested one of the skippers we use by sending up a yellow bouy. You should have heard the engines scream as he roared over. Down came the bottle. Mind you he had the right roaring hump. Cost us a few beers!!!!

We are all as a group religious about getting back to the shot. NO bagging off unless a real emergency. Therefore diving off a hardboat and all doing similar run times give or take a few minutes, we are all in close proximity on the accent phase.

I understand your sentiment about being P***sed off about helping someone out who only carries 3's but then we are a team who have been diving together for a few years.

Plus i have a slate with " How much is a 7 of 18/35 worth" written on it!!!!

Its all down to why do you use a rebreather.
Me personally, my old knackered back was getting cheesed off with carrying 2X12L's with 10's side slung.
I cannot see the point of having a rebreather and then attatching shed loads of OC gas, it sort of defeats the object.
If you prep the unit and do all the predive checks, change scrubber and monitor cell life, you have a good chance of beating the varmint!!!

Oh well i await a castigating from the list, but these are just MY thoughts.
All the best
Tim B

Mark Chase

I am constantly amazed how the rest of the world can be so wrong and only I can see the truth

ATB

Mark Chase

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Timbo

sorry Mark i do not understand your post

nmanfield

Totally agree with you, IWR is always the last option IMHO, but there may be times that it should be considered a viable option (and not an excuse for poorly planned bailout strategy). It should be considered as separate - i.e you get back at the surface and notice 'niggles', you have an uncontrolled ascent or you do something seriously numpty-like or heroic. I certainly don't advocate IWR as a sort of 'morning after pill' and it should be considered a dangerous activity in itself that needs to be carefully controlled and the risks mitigated as much as possible. We all plan out bailout strategies ( i hope!) but how many of us consider an IWR strategy, I wonder (I for one don't but am seriuosly considering it from now on)

Regards,

Nick

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