Drop Bottle

[nickb]

Originally Posted by DecoWarrior

just to add to marks diagram, we always found that using a waster witha prussock (sp?) know on and a spinnacher release clip that will still release under load is a useful safety addition

Prusik Knot

Snap Shackle

[Scubee]

thanks for that link, Nick... a brilliant website - green incoming

[ardhill]

Originally Posted by al kennedy

- Take enough back-gas to cover one lost deco bottle.

Not always possible. Try planning a 50m wreck dive, with enough gas in your twin 12's to have your dive on the wreck and complete your deco safely. How long did you get on the bottom? Not very long, and in my opinion, not long enough to warrent paying the money for the charter boat to the site. Don't cheat and use your lowest SAC, use your normal 'plannig SAC' - I use 20LPM to plan.

- With two deco bottles plan that each contains enough to allow you to deco on back-gas and one deco bottle.

In some instance that would mean me taking 2 x 10L deco tanks to give me what I can do on the bottom for twin 12's. I don't have any 10s, and a drop bottle is a cheaper option (especially since I have the 7l already).

- Is there a way to access the gas in the 'lost' bottle (assuming it hasn't vented away completely)? Regulator failure - swap regs? Hose failure? How do people envision that gas is going to be lost? Would a spanner be a more useful (and reliable) tool than a drop-bottle? Or a spare mouthpiece solve the problem?

I am more interested in planning for a total loss, eg you have unclipped your tank, and dropped it whilst mid water. I have also seen on 2 occasions a 1st stage problem so bad, that the diver lost all his gas before completeing his deco. On both those occasions, I was able to gas share. Also remember a deco tank had generally only 1 reg, not everyone is happy to be able to buddy breath whilst holding a stop.

If you get separated and then lose deco gas you are having a very bad day.

Your right, but I have lost bddies enough time to know it can happen. And as I said above, I have seen a diver loose all his gas before completing deco twice. So these things do happen.

At which point does planning for multiple failures become counter-productive (i.e. plan becomes overly complex with a greater risk of failure, or you need ever increasing amounts of kit)?

When it becaomes more trouble and expense than it is worth. Or the chances of that failure, or multiple falure is so remote, it is not woth planning for. IMO, a drop bottle is worth plannning for and as I don't need to take it in the water with me, it doesn't give me any more problems.

If you have planned to account for loss of deco gas as above, then you are no longer reliant on a buddy. (And what if your buddy has problems too?)

I don't expect a buudy to bail me out on any dive. If they do, then great, but I plan to be self sufficient as much as possibe.

If we both loose deco tanks, and each other and other divers, then one of us is going to get bent or worse. But that starts to get into the realm of 'not really likely to happen'. But even if it does happen, at the end of the day diving has it's dangers - deco diving even more so. I have thought about dieing in the water . It isn't nice, but I know it is genuinely possible. If I couldn't stand that possiblility, I would curtail my diving to the risk factor that I was able to live with.

[Mark Chase]

Snap Shackle



The above is exactly what we use. Be warned that if you use a rope loop in one of these and the tide is running the loop can get caught on the end of the shackle.

End result is you have to cut the rope loop to let the lazy shot (trapeze bar) drift with the tide

Its better to use a large SS ring in the shackle then with a twist it will usually come off no matter what the tide is like.

ATB

Mark

[DecoWarrior]

cheers nick thats the one,

yes the point i was trying to make is dont fasten the shot onto the shotline by the clip as in a tide your station clip will lift up and defeat the point of having a station

well it depends on the rope and loop we never had one sieze, but differant strokes for differant folks...

[Mark Chase]

Originally Posted by KiwiMagic

Enjoyed reading and learning from this thread. Definitely something I will have to give more thought on.

Just a couple of questions.

If you carried enough bailout to complete the dive (if something went wrong at the worst point) would you still go down this route?

If someone did have something go seriously wrong and a tank had to be deployed, wouldn't a diver go down to see if help was required (I appreciate that this take time and wouldn't be used instead of, but as well as)

People have mentioned a trapeez for deco and I know how they work in theory, but have never seen one outside a picture. Could anyone show me how to make one, or show me a web site that does this?

Sometimes carrying enough bailout is a hazard in its self. We operate a yellow bag system. In the pic where you see Janos on the drop tank, I sent up a yellow SMB which has SEND GAS written on the side. The skipper got the drop tank and clipped it to my SMB line and dropped it (still attached to a float just in case)

I then carried the tank over to Janos and we clipped it off to the bar.

For this 45min @ 65m dive we carried a Steel 10 of 18/45 and an Ali 80 of 50%. The drop tank was 80%. Janos could have used my Ali 80 of 50 to complete the deco but the 80% sped thing up.


We were all on deco there was no safety diver on the boat to come down but using the trapize ment there were 10 divers arround all with gas. I like to use a trapize on all dives below 60m for this reasion.

The down side is all divers must return to the shot. In UK viz that usualy meens laying a guide line back.


A buisy deco bar is a safer place to deco




ATB

Mark

[daveb0000]

Originally Posted by Scubee

He's your mate...twist his arm
or....I could bribe him with chocolate cake


Will he sell up if I show him my puppies?

I would of sold my seven steels and got ali's but i'm skint at the mo

mind you, you have the sweetest puppy's i have seen