In the last couple of years when I have been stepping outside my regular GUE bubble I have been exposed to other ways of navigating caves. Most of them are ok, if a bit stupid, but some are downright dangerous and will kill you given enough time.

The right way to do it

I hope this title was elitist enough to make you keep reading. I have no cave instructor cert to sway you with, so an elitist tone will have to do.

The right way to do it is super simple and can be summed up in one sentence; “Put a personal non-directional marker at the exit side.” A personal non-directional marker is anything that only has a directional meaning for you. In other words, it doesn’t point in any specific direction and is personalized. So it can be, and usually is, the round plastic bit we call “cookies” with your initials. It could be a stage with your name or other personalized equipment you can drop on the line. What all personal non-directional markers have in common is that it is where it is that gives in navigational value, not what it is.

You can sum up the rule as “leave shit on exit side”

Navigation on a T

• Everyone in the team leaves a non-directional marker at the exit side of the T.

Navigation on a jump from a system arrow

• Everyone in the team leaves a non-directional marker at the exit side of the system arrow that soon will become a temporary T.
• Connect your jump line to the system arrow.
• if no system arrow exists, place a personal arrow.
• if no system arrow exists and you have passed a change of direction, and you think other teams might come here, use a cookie to secure the jump (still place a non-directional marker at the exit side)
• if no system arrow exists and you have passed a change of direction, and it’s so deep in the cave that you don’t think ist likely with other divers, use an arrow to secure the jump (still place a non-directional marker at the exit side)

Navigation when the jump creates a temporary T on the line you connect to

• You put your non-directional marker on the exit side of the temporary T, in other words, the jump line you just installed.

The dangerous ways to navigate

Trusting the caves directional markers (cave arrows)

A cave can, and often have more than one point of entry. When a cave has more than one point of entry, the system becomes complex. And the system arrows will not always point in the same direction. When you experience a change of direction, relying on system arrows alone goes from dull to potentially fatal. You will not know how far it is to this entrance or what kind of condition the exit is in. Cenotes can come in many forms. You have no guarantee you will be able to use it. It might need line repairs, or it might be behind a nomount restriction your not equipped for.

If you trust system arrows and only use cookies to count divers using that jump-line you are risking your life, and you are not taking advantage of the extra security the cookies can provide for you. But people don’t do this stuff you might say. You are just putting up straw-man arguments! I wish that this was true, but in this famous blog post named Don’t be a cookie monster they manage to put all the cookies in the wrong place when explaining how to use them:

The rationale for doing it this way is often said to be so you know if your lost buddy has exited the cave or not. But this is a dangerous practice because it indicates that the absence of a cookie means it’s okay to remove equipment. Personal non-directional markers should only be referenced by the person putting it down. Don’t kill your lost buddy just because (s)he was not great at securing cookies on the slack jump line. If you have “misplaced” your buddy and you’re out of gas to continue your search, you leave all the equipment installed and drop extra arrows indicating the exit. And pray you to meet your buddy worried sick on the surface. You don’t remove jumps because you can’t find cookies on them.

Instructors that teach non-directional markers next too the spool usually also teach not to trust system arrows. Or at least not to trust them in all instances. So you then learn to use your personal-directional markers (arrows or REM) at jump when the system arrows points in the wrong direction. All cave-divers dives close to the entrance at the beginning of their career, and this develops their navigation behavior. If they trust system arrows, without reinforcing them, at the beginning of their career this habit will be hard to break. In more remote parts of the cave system, system arrows will start pointing towards other entrances, and your exit needs to be reinforced. If your navigation practice from earlier needs to change, your chance of fucking it up increases dramatically.

Where it got all screwed up

Cookies have a secondary feature when everyone drops their cookies you can see who is in the cave. That’s great, but it’s not the primary purpose. The cookie exists so it can reinforce your exit. And this is where I think it got all screwed up. Somehow someone got hung up on this secondary feature and forgot the primary purpose of reinforcing the exit. It’s not dangerous to add a cookie to your jump line. I feel it might be redundant as your spool should be marked and personalized, it’s not dangerous as long as it’s done in addition to a non-directional marker on the exit side.

TDI Cave Instructor Nat from UnderTheJungle has an inDepth blog post explaining a lot of different ways to navigate in a cave. Yet what stood out to me in this excellent post was that navigation isn’t standardized, not even inside agencies. To quote “While agencies may have general guidelines, navigation procedures are left up to the instructor.”. So when one instructor misses out on the finer details on why we use cookies this dangerous practice starts to establish itself in the cave diving community without any checks on it.

The same goes when instructors only dive and teach in systems where there only is one exit like in the cave Plura in my home country Norway. (This is not technically true, but only a handful of divers have dived to the other side). Since there aren’t any other exits in the system, system arrows can be trusted a whole lot more than in more complicated environments like Mexico.

It should be obvious that the practice that should be taught is the one that is used also in the more complex systems. After all most cave divers travel to pursue their passion and will probably be exposed to other caves than the ones they trained in. That agencies like TDI, IANTD NSS-CDS, RAID, PSAI, and even GUE* don’t have a navigation standard for their instructor is probably something the instructors enjoy because then they can teach it exactly how they think it should be done. But this robs their student from a decent minimum standard when the instructor isn’t really on top of good navigation practices in complex systems.

Silly navigation practices

There are some practices I find a bit silly, but not exactly dangerous. The first one I have touched on earlier, putting cookies next to your jump-spool. You do this to mark it. This cookie enforces that this is your jump. If you properly mark your jump-spool, as you should, this will be unnecessary. There should be another set of personal-markers where you tied in. If a team accidentally picks up the wrong jump spool they should understand that they have done something stupid when they see your team’s personal-markers on the other side of the jump (0.5-30m away). The further your from other divers, the less this practice makes sense.

The second one I want to touch on is the use of REMs or directional non-directional markers as I like to call them. The only problem I have with them is that they are redundant while adding to the complexity. Hick’s law tells us that the reaction time increases logarithmically with the number of choices. So adding an unnecessary extra tool to the navigation toolbox will logarithmically reduce how fast we know what the right solution is. Since the REM has a direction, it also has to be put down the right way. Cookies only have to be placed on the right side. REMs need to point in the right direction as well.

So when would it make sense to use a REM?

• On a “T” a cookie is more appropriate as it has no direction and you can’t put it down the wrong way. You only have to remember to put it on the exit side.
• If you do a jump from a system arrow the same applies.
• What about an unmarked jump? Now it starts to get interesting. But this can be solved with a personal arrow and cookies, so it’s similar to the system arrow example. But putting two markers is slower than one! That is true, but the additional overhead of having three instead of two personal-markers is probably slowing you down more than the five extra seconds it takes to install two instead of one marker if you are conscious of how you use them.
• But when should you use a REM then? If you have passed a change of directional marker and want to jump on an unmarked jump a REM can make sense as it does not change the direction of the system. Putting an arrow pointing to your exit might confuse other divers. This is not a very common scenario. And you are then often in parts of the system that see very infrequent traffic so an arrow might work, but if you fear that it will be other divers there you can anchor the line with a cookie and put cookies at the exit side of this new temporary intersection.