3 ms·

Do the guide lines have any indicators that would show which way goes further into the cave and which way heads toward the surface?

gaius 8y ago
Yes, triangular plastic line arrows, you can tell just by feel which way to go if you are totally silted out - provided you can find the line itself
deleted 8y ago
[deleted]
callahad 8y ago
Most popular caves have permanent lines installed with arrows every ~100 ft or so, maintained by the local community. A common convention is that the main / most navigable path through a system uses a slightly thicker, yellow nylon line (the "gold line"), while side passages tend to use thinner, white nylon. Divers are expected to bring their own reels and markers into the cave to make and mark temporary connections, for example, from open water to the gold line, or jumps from a permanent line into side passages. Reels are also useful tools for locating lost guidelines in zero visibility. There's an overview of various line markers at https://www.tdisdi.com/cave-diving-directional-and-non-directional-markers-101/ https://www.tdisdi.com/cave-diving-directional-and-non-direc..., and a great photo of line arrows and a gold line / jump reel connection on Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Line_arrow.jpg https://commons.wikimedia.org/wiki/File:Line_arrow.jpg The trick is, the permanent arrows indicate the closest "exit" to the system, so if there's a 1000m cave connecting two freshwater springs, then at the 500m mark you would usually encounter two back-to-back arrows, one pointing to each exit. The trick is, if you haven't personally explored both exits, you can't be certain that they're both navigable. So if you're 750m into that system, lose visibility, and need to get out by feel, you have to find the nearest arrow and then blindly swim in the opposite direction from what it says is the exit. It's... "fun."

gaius 8y ago

Yes, triangular plastic line arrows, you can tell just by feel which way to go if you are totally silted out - provided you can find the line itself

deleted 8y ago

[deleted]

callahad 8y ago

Most popular caves have permanent lines installed with arrows every ~100 ft or so, maintained by the local community. A common convention is that the main / most navigable path through a system uses a slightly thicker, yellow nylon line (the "gold line"), while side passages tend to use thinner, white nylon. Divers are expected to bring their own reels and markers into the cave to make and mark temporary connections, for example, from open water to the gold line, or jumps from a permanent line into side passages. Reels are also useful tools for locating lost guidelines in zero visibility. There's an overview of various line markers at https://www.tdisdi.com/cave-diving-directional-and-non-directional-markers-101/ https://www.tdisdi.com/cave-diving-directional-and-non-direc..., and a great photo of line arrows and a gold line / jump reel connection on Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Line_arrow.jpg https://commons.wikimedia.org/wiki/File:Line_arrow.jpg The trick is, the permanent arrows indicate the closest "exit" to the system, so if there's a 1000m cave connecting two freshwater springs, then at the 500m mark you would usually encounter two back-to-back arrows, one pointing to each exit. The trick is, if you haven't personally explored both exits, you can't be certain that they're both navigable. So if you're 750m into that system, lose visibility, and need to get out by feel, you have to find the nearest arrow and then blindly swim in the opposite direction from what it says is the exit. It's... "fun."