Line Protocol/Cave Navigation: Are We All Really On The Same Page?
Formalized cave diver training attempts to bring a level of standardization necessary to make sure all cave divers are on the same page about the basics. By the basics, I mean preparing you for anything that can kill you before getting out of the cave safely.
One factor that significantly affects safety, and what I want to touch on here, is line protocol and cave navigation. Anybody can enter a cave. It takes a person with great skill to get back out (as evidenced by the number of deaths we've seen). Navigation by use of permanent lines, line arrows, & non-directional markers are often the means of accomplishing this end. But are we all really on the same page about the same thing that could potentially kill all of us the same way?
Let's take one example and follow it through to see what I mean. This scenario was lived out in more than one real-life dive by me. I wasn't leading, but the lead diver proceeded to mark a direction decision point in a way that I felt was incorrect. NOTE: I'm not a cave instructor. But I can die in a cave just like they can. You don't have to build experience to die in a cave. So I make sure my convictions are based on sound logic. The fact that I put my own butt on the line by cave diving myself gives me the right to speak up on the subject.
Not only have I seen this happen in real life, I have also participated in message board discussions where "certified" cave divers were in disagreement with the correct course of action to be taken. Let's get down to specifics.
We enter a cave with multiple entrances. Our dive plan is to run up the line 1,500 ft and make a jump to the left. The entire cave is VERY silty with a low ceiling, making a zero vis exit quite probable. This is our first time in this cave system. Our team approaches the jump and we see a scenario like Scenario 1. The line arrows are indicating there is an exit closer than the one we entered from.
The jump looks quite elementary, right? Wrong. Scenario 2 is how I've seen this jump marked in real life and the way some have advocated on message boards - with no additional personal line markings.
Here, it appears the lead diver is saying in case of dire emergency, follow the line and arrows to the closest exit. Even if he didn't mean to communicate this and intends to exit from the hole he originally entered, this line marking can be confusing to the other members of his team and even to himself if all vis is lost.
Our own observations (visibility) coupled with memory during the dive is our primary direction-finder, while permanent lines are our back-up in case we get confused or vis is lost. Here is a dive plan where vis is sure to be lost, and memory may fade since this is the first time the team has been in this cave. To add to the problems, now the lead diver has pointed the team to an alternate exit. Whether intentionally or not - it's still a potentially deadly mistake.
Obviously a visual jump would be suicidal. So instead of marking the jump like that in scenario 2, I recommend marking it like scenario 3 using a cave cookie and seperating it from the line arrows by several feet. Placing the cave cookie on the EXIT side of THIS team's entry point offers no contradictory information to this team or other teams in the area. So it reduces confusion. It says "This way is the way my team came in, and this way is the way we're going to exit, regardless."
Since the cookie is a non-directional marker, it does no good to tie directly into the cookie, like you would an arrow. It would offer no confirmation of the direction from which you entered. Likewise, I would not recommend placing the non-directional marker on the inside of the jump. I have heard of this being done in Mexico as an indicator to stop, that you're going the wrong way. This would be in violation of every cave diving text I've read. All cave diving texts are in agreement that even non-directional markers should be placed on the exit side if they are being used to confirm a preferred exit.
Using a cave cookie as opposed to a clothespin is preferrable. The clothespin has always been subject to currents, bumping, or simply falling apart. If the line were to break, then your clothespin would very possibly fall off as well. A cave cookie can be secured by double wrapping just like the line arrow can. Just like line arrows and clothespins, cave cookies should be marked with the diver's initials. You should never follow a line marker of any kind that is marked with someone else's initials unless you are a member of that dive team who placed it there.
I was once in favor of using a personal line arrow pointing in the opposing direction of the permanent arrows when setting up this jump. But with the increase in popularity of cave diving and increased diver traffic, line contradictions and multiple team confusion has become an increased concern. Any temporary markers should be removed at the end of the dive unless you are setting up a traverse or circuit. In that case, it should be removed as soon as you are finished, so as to reduce line clutter.
Deciding to use an alternate entrance as your exit can be a very dangerous decision, unless you know the system very well. The alternate exit could have collapsed, silted out, or the line stop short of the daylight zone. The alternate exit could also be another jump or two further and may not necessarily be on the same line you are currently on. If you planned your dive and dived your plan, then you should have plenty of gas to get back to your original entry point even in an emergency.
In any event, I think it's very important for the dive team to have some sort of confirmation of the direction of his team's exit. And I think there's a way of doing so to ensure the team's safety while at the same time not causing confusion to others.