Primary light won't light ...

[karstdvr]

The 3 light rule doesn't get broken, ever. None of the "golden" rules of cave diving get broken, ever.

I think that pretty much sums it up

 

[LiteHedded]

Lol you should see those Mexican cave rodents of unusual size! :mooner:

I love a good princess bride joke

 

[Dive-aholic]

There's a little Mexico vs. Florida stuff going on here . . . At least in the Florida caves I've been in, there's a tunnel and a line in it. There are jumps into other tunnels with line in them.

In Mexico, you can have a broad, flat room with a lot of speleothems in it and some spiderwebby routes you could take through them. You could get a long way away from the line, and possibly lose track of it, without having to silt out to do so. They're just really different caves.

There is a difference in the caves, but Florida caves can have some pretty big rooms, too. I rarely swim the line in a cave anymore. But I'm always aware of where it is. Even in a Mexico cave, if I'm going to be taking a spiderweb route through some formations, which means I'm likely to lose reference to the line, then I will tie into the line with my spool.

Gee that sounds like fun, a dim cave dive.

It's actually a lot of fun. I've done a chemical light dive. It gave me a different perspective on the cave. I noticed things I hadn't noticed before with my HID. Sometimes narrowing your focus helps you see more...

A few years ago a woman in a Cave class in MX found a new passage by losing bouyancy and ascending up into a hole while on a backup or in the dark (I can't remember which). She stubbled around in there for quite awhile. The instructor and the class were going out of their minds cause they could hear but not see her. Even after turning on their primary lights (when they realized she was missing). Eventually she came out the other end of the new unmapped parallel tunnel and survived.

So yes its quite possible to lose the line in circumstances other than a siltout. With decent awareness and a decent light you can just turn around and the line is probably there. With a lessor light you are just starting down the incident pit. Nowadays IMO lessor is <10W HID power and less burntime than the duration of your gas.

Very rare and unlikely occurrence. If she was in the dark, why was she not on the line to begin with? Did she deploy her safety reel? I agree with half of your statement - with decent awareness you can just turn around and the line is probably there. Like I said, I rarely swim the line, but I always know where it is.

 

[TSandM]

Even in a Mexico cave, if I'm going to be taking a spiderweb route through some formations, which means I'm likely to lose reference to the line, then I will tie into the line with my spool.

Well, that's my point. I was just saying that it would be possible in some places to get out of sight of the line and lose it, without having to create a siltout to do so. In that case, having a light to find the line again would be quite useful. (This was purely in response to the idea that the only time you'd be doing a lost line search would be in zero viz.)

 

[rjack321]

Actually step 1+2 in a lost line drill is using the light and covering it to try and re-reference the line without getting to the safety spool stage. No or a weak light limits those options.

I don't necessarily think you need a goodman yada yada. Although I haven't done a dive without a canister light in ages so I'm not really sure of the alternatives today. I just think you need decent power and decent burntime. A 1W LED or halogen scout is definately inadequate (to enter with). A 3W LED torpedo/Heser might be ok depending on the cave. Still kinda marginal IMO when combined with the handheld factor though. A 10W handheld HID has adequate power I just don't know about the handheld factor.

You still need 2 additional backup lights.

 

[Dive-aholic]

All of my lights have at least 4 hour burn time. My mask light has more like 6-8 hours on it, the first 3 hours bright enough to serve as my only light if it came down to that. My Intova 3W LED is pretty bright and compact enough to not be an issue. The 10W handheld is definitely too big IMO to go as a primary without a handle attached to it.

I'm not advocating going into a cave with suboptimal lighting. What I'm saying is the options out there are a lot better than they used to be. When I did my cavern class I used an SL6 as my primary. That was bulky and not very bright. I bought an HID a month later. But with the new LEDs, things are different. I've seen an LED used in dry caving that can light up huge rooms. And it was only $20!

Well, that's my point. I was just saying that it would be possible in some places to get out of sight of the line and lose it, without having to create a siltout to do so. In that case, having a light to find the line again would be quite useful. (This was purely in response to the idea that the only time you'd be doing a lost line search would be in zero viz.)

I get that. I just don't ever see myself getting into that situation. If I have visibility, I can get to the line.

 

[rjack321]

I get that. I just don't ever see myself getting into that situation. If I have visibility, I can get to the line.

A friend's cave class surfaced in a place called DCS dome in MX. This is a breathable air dome (which has no access to the ground surface though). The line rises from 35-40 up the sides of this huge breakdown pile and then goes over the top in 3-4ft of water. Back down the other side to 35-40ft.

Anyhoo. The plan was to surface in this dome and check out the cool roots hanging from the ceiling. The class surfaced. They check it out and decide to descend back to the line at their feet. The go under to discover they are on the line but disoriented as to direction. The class lesson was to use an arrow+spool to jump off the line even when its still obviously "right there".

So my humble advice is to treat every dive like unexpected poo can happen. And even if you have light and return to the "lost" line, you might be facing the wrong direction and waste valuable exit gas+time reorienting.

 

[OneBrightGator]

Actually step 1+2 in a lost line drill is using the light and covering it to try and re-reference the line without getting to the safety spool stage. No or a weak light limits those options.

Cover the light to find the line? Gonna have to explain that one to me.

First, if you've lost the line, then you've already screwed up. Second, like I said, what if your primary dies and you lose the line on the way out? Gotta be prepared.

 

[PfcAJ]

Cover your light and look for your buddy. If you strayed off the line, hopefully your buddy didn't and you can make way back to him/her. Lost line isn't always in zero vis.

 

[Michael Schlink]

OK so can someone bring me up to speed here.
The OP asks if you can START a dive on a backup which the correct answer is, you start a dive with 3 lights and the first one you start with is your primary and it should be bigger than a candle and it doesn't have to equal the sun. And a lot of folks think it should have a Goodman handle rather than being a broomstick. Is this all correct so far? And then we went down the road of which rules are OK to bend or break and that answer is none of 'em. And now we are looking at lost line scenarios and how we are going to use a back up light to find it?? OK everybody that's cave trained raise their hand. Now everybody that actually cave dives more than a couple times of the year raise their hand.
Last I looked most of the problems encountered while cave diving have a protocol for solving and/or preventing it, If your primary dies you switch to back up, signal team and thumb the dive, diver on back up goes to the middle or front, and exit cave. Good so far. Next at anytime if you can't reference the line, stop where you're at, calm yourself down (because a lot of you just got a little bit excited) and look for the line and/or your buddy, sure you can cover your light, for a few seconds, if that helps. Then tie off a safety reel and start looking for the line, now here's the important part FIND the damn line your looking for in about as much time as it took you to lose it and then check gas, check @ss, and decide which way to go. If at any time you have to depoy your back up during another drill solve the first problem and then follow light failure protocol.
We all good now.
I would encourage anyone who doesn't get to cave dive regularly to stay within arms reach of the line and preferably above it. If you aren't fairly experienced, and without meaning to insult anyone here, a recreational cave diver, you should stay closer to the line then you probably are.
JMHO opinion and I truly don't mean to sound mean or offend anyone.