In times of GPS tracking and route planning devices in every car, most people have gotten so used to them that they are lost if they don’t work properly. I know I am. Because when I drive somewhere and rely on my device to tell me the way back, I will not pay much attention to the routes and landmarks along the way.
In diving, we start talking about this special type of awareness when the student starts with more training beyond the open water diver. We want to build up skills to recognize patterns, landmarks, and special features on the reef, so if we have to return to our entry point, we find the way without much delay.
During AOWD training, when we talk about navigation, we always encourage divers to look back to memorize the way they came from. We use natural navigation but also eventually use the compass as an additional navigational tool, and always look back at a special coral formation so you recognize it from both sides.
In cave diving, we rely on diving in the proximity of the line, and the line will guide us out after turning the dive. This is how we stay safe in the overhead, but this isn’t the full picture of how an experienced cave diver navigates in a cave.
For simple dives along a main line, such as during intro-to-cave training, the back referencing techniques can be held fairly simple.
When installing the primary line, look back to the entrance that you did not create a line trap with the line you just installed. Take note of the time it took you to connect to the main line and guesstimate the distance, and most likely you will see that you can swim out of the cave much faster in case of an emergency, when the temporary line is not removed, than it took you to install it.
Our first reference would be that we know how much time is approximately needed in case of an emergency to exit from this point.
Proceeding further into the cave, we take note of sharp turns, pronounced depth changes, and can write these down, creating every time a way point that we simply match time-wise on our way out.
In caves where there are permanent markers installed on the lines, we can use these as our waypoints and create a first (mental) map of the cave. We additionally get information about possible side tunnels and jumps as we learn to distinguish between distance markers and markers that indicate a jump. Again, we take note of the direction of markers, colors, and relative position to tie off points and memorize it and write times we needed to reach the marker on the way in. On the way out, we simply backtrack our steps and make sure that differences in times in are matched on the way out (or as I learnt to be a bit faster on the way out as in).
But experienced cave divers look beyond the lines and recognize the differences in cave passages, whether it is from flowstone formations, the shape of tunnels or the colour of cave walls and sediments. The cave starts telling us a story, and when we are ready to listen, we create not only an excellent map of a cave, but also learn a lot about how the cave was formed. A famous saying goes: Dive the cave, not the lines. I create a mental picture of room after room that looks so distinctive that I have an excellent back referencing point on my way out.
Referencing markers along the line is usually acknowledged by the team, as well as later in training or while doing more complex cave dives, any navigation needs to be acknowledged by the team, no matter what kind of marking protocol you use, namely, team vs individual marking. Each navigation is set up so that the exit side is always clear, either by putting a cookie on the exit line of a T, or by just the fact that your temporary line is the line that connects your continuous line back to the open water, or by Tieing into your arrow when you start a jump.
There is, however, not a specific signal needed to communicate in between the team members that each has completed the back referencing and overcommunication actually can lead to misunderstandings.
I only ever would use the signal “way to surface” if I asked my team member a question to where the exit is.
Like in intro-to-cave diving along a main line, we now can use the same back referencing techniques that we started to learn and implement then, however, taking extra note on the navigational decisions as a special waypoint. It is a good practice to stop and write this information down in the beginning, so back-referencing techniques can slowly build up and improve.
When the team has now turned the dive and returns to the exit, tracking back the times they needed from one navigation to the other is a great back referencing technique that helps each diver individually to determine if they are in time, on the correct route and helps to find out any mistake very early if they made a wrong navigational decision on the way back. Each diver tracks it individually and while the first diver will signal “way to exit” when passing a navigational decision, the team leader as last diver retrieves the jump line (of for what it is worth any other navigational markers. Again, there are differences between individual and team marking, but the procedures for back referencing stay the same.
My personal approach to teaching cave diving and diving the caves is also to minimize communication to the minimum needed and not to produce possible miscommunications. But most divers need to learn in the beginning to look at the dive as a whole and learn what it takes to know exactly at any point of the dive where in the system they are. Back referencing along with reading maps, making a thorough dive plan beforehand, debriefing and logging the dive information are the tool to complete this task.
If this sounds now very complicated and you are confused, let me assure you, it is not and I would be more than happy to explain you my approach during a workshop and a couple of guided cave dives (when you are already certified) of during training. Let me know either by whatsapp or email.
