How often do you run a line?

[aainslie]

Safety diver on each dive that put in ALL jumps. The videographer didn't want the detraction of a reel placement,except at Cow. The safety diver put everything in,and the plan was choreographed such that if the safety diver couldn't complete a part of his task,the whole dive was dumped. I hated this when a couple places had to reshot,but in retrospect I appreciated the safety diver. Hence due to the proximity of the safety diver,and working as a well choregraphed team,I had a continuous line to exit,and this was needed for the nether reaches of Bonnett.

a) Nice story!

b) Even if it were true, how could you condone a video for sale to anyone (regardless of training) wherein it appear that jumps without a reel are OK?

[aainslie]

I support that idea.

That will only encourage blind circuits. Even more than they're currently done.

...Hmmm... i see another poll coming on...

[Sludge]

I miss Karl.

[RN]

does that EVER happen? are we planning for unrealistic failures here?

Using that logic means no one should ever run a primary at Devil's or JB because no one has ever died from not running a line in those places...

It is possible to have a catastrophic gas loss at or close to your farthest penetration. And when a loss occurs I guarantee you won't get situated as quickly as you might in drills. It's completely different when you have a jet stream of air propelling you around the cave while you're trying to shut down your valves losing site of the line because you will silt out the passage. Thirds is not conservative enough for 2 person teams, even in high flow systems. I am confident I will have enough gas if I have a 1st stage or valve failure. If you want to see more of the cave, improve your consumption or bring a stage but don't dive the extreme limits of your gas volume.

[LiteHedded]

Using that logic means no one should ever run a primary at Devil's or JB because no one has ever died from not running a line in those places...

It is possible to have a catastrophic gas loss at or close to your farthest penetration. And when a loss occurs I guarantee you won't get situated as quickly as you might in drills. It's completely different when you have a jet stream of air propelling you around the cave while you're trying to shut down your valves losing site of the line because you will silt out the passage. Thirds is not conservative enough for 2 person teams, even in high flow systems. I am confident I will have enough gas if I have a 1st stage or valve failure. If you want to see more of the cave, improve your consumption or bring a stage but don't dive the extreme limits of your gas volume.

I know. I've had it happen. it's no fun.
well...i wasn't propelled around the cave. but i've had to shut down a post on a dive or two. certainly not as smooth as a valve drill

I'm just wondering if you'd ever lose all your gas. nothing wrong with reserving more than thirds at all. I often do. I'm just wondering if, out of all the good reasons to save more gas than thirds, is losing all your gas at max penetration one of them?

[RN]

It is one of them for me but not the only one.

[Marc Bryan]

A good solution to this would put a "T" at all the popular circuits (loops) like the "Merry-Go-Round" at Little River.

I agree.

[wingman]

a) Nice story!

b) Even if it were true, how could you condone a video for sale to anyone (regardless of training) wherein it appear that jumps without a reel are OK?

Andrew, that's a little over the top...i'm sure it is exactly as kelly described and your point about the illusion of visuals and that message is well taken.

There are certainly times when a visual transfer from one continuous line to the surface to another is fine (at least to me). For example a roller coaster circuit at ginnie. Put in a real going into the roller coaster that you pull on the way out. Go to the end of the roller coaster line and visual onto the gold line and exit via gold line. That 10 foot or so jump from one continuous line to the surface to another does not require a reel. The dogleg (coat hanger) is in a large dome room with good vis and high flow. Granted the exit via the roller coaster is a bit quicker but by only a minute or so, this verified by a test. Why would anyone put in a reel from the end of the roller coaster to gold line on that circuit? If scootering a whole different set of incremental risk calculations arise. All those risk calculations require judgement and experience. For those whose judgement and experience are not well developed decision making using the rule always run a reel works well. Bill

[Marc Bryan]

I would also propose that it is higher than 1/3 doing visuals at Ginnie, especially to and from the gold line, if you do not count classes/students. With the thousands of dives done there every year that is a pretty large data set of its own. Not saying it proves you shouldn't run a continuous line. Maybe it just says a lot of us are really stupid, dangerous, lazy, etc......

I do agree with Andrew that there is a lot of do as I say not as I do, in this community. I have personally dove with many who do not put lines in at gaps while doing the Grand Traverse at Peacock, but still tell others that they should always run a continuous line, or a line to O/W, etc.....

I disagree with Marius (and I dive frequently with Marius) that not running a reel from harry's crack to the gold line was a large contributing factor in the recent incident. Even if he missed the gold line, and if visibility was zero, and he accidentally ended up on the hill 400 line there are several indicators of exit direction. First is the flow and the fact you would have been swimming against it. Second, he would have only had to swim the line 60ft before hitting a distance marker. If he missed that, in less than another 100 ft he would have hit the two jump arrows at July Spring. Of course this is just my opinion, and we all know what that is worth.

Great discussion, and I would like to thank all for keeping it civil and at least semi productive for me.

[aainslie]

Any instructor that teaches that "your immediate reaction is to isolate" doesn't really understand how doubles work. Of all things that go wrong with gas delivery underwater, something that would be solved by isolating probably happens 0.00000001% of the time.

(I've never heard of it happening.)

For starters, I think we're on different tracks. You're probably talking about closing the isolator valve, I'm talking about isolating the gas flow. My bad, I wasn't clear. Often the best way is to shut down a valve, not the isolator.

I suppose "isolate" is also different with different configs. With sidemount, I definitely isolate first. Why not? It's so easy - and it cures any problem except a burst disk, giving you time to work out a) your options, followed by b) is any of the gas salvageable, perhaps by feathering or changing the reg out? Sometimes it's as simple as stopping a freeflow caused by scootering.

But personally, gas comes first for me. I first stop the gas exit, then worry about the rest.