People write books about cave navigation. That is pretty stupid as it is really simple. Always use a guideline and leave shit on the exit side of intersections. GUE has a bit more verbose way of saying the same in their SOP all GUE divers follow:

Cave Navigation and Marking Protocol

• Divers should always use the guideline to travel and reference their location.
• It is the team’s responsibility to always ensure that it is following a continuous guideline.
• Ideally, divers should never be further than arm’s reach from the guideline. Some scenarios where this would not be practical include high-flow caves and areas where the line is close to the floor and the distance to the ceiling is high (assuming good visibility exists).
• Jumps, permanent intersections, and initial change of direction markers are marked by all team members.
• Non-directional markers (cookies) should be placed on the exit side of the intersection.
• Directional (arrows) and non-directional markers do not need to be numbered, but should be labeled with the initials of the diver placing them.
• Visual jumps, blind circuits/traverses, and “trust me” dives must be avoided.

Personal notes

I think the GUE SOP could be a tad clearer too be honest, especially when they first choose to be this verbose. It’s not entirely clear what to do when you create an intersection with a jumpspool to the middle of another guideline. Changing the wording so it’s clearer that we talk about all sorts of intersections. Permanent and temporary.

• Non-directional markers (cookies) should be placed on the exit side of the intersection.
• Non-directional markers (cookies) should be placed on the exit side of all kinds of intersections, permanent and temporary

But otherwise, I’m pretty happy I don’t need to read a book on cave diving navigation to understand it.