I've heard this comment a few times, so let's get into it!
Remember a time you drank too much before going to bed (water, of course) and waking up in the night needing the bathroom. Did you need to turn on the light? Did you know where you were? Can you visualise the route to the bathroom? All you needed was the knowledge of the layout of the place and where you were in that layout.
That level of knowledge comes from the amount of time spent in that environment and absorbing the details of the place. This is an example of a place you know very well and can easily find your way even when you can’t see.
Getting Around On Land
Let’s take this idea further and think about a drive to work or to the supermarket. The first time you drove this way, you likely relied more on maps, GPS & road signs. Over time and the more you make the journey, you recognised more of the signs and the layout of the streets and buildings you pass. You become familiar and built a picture of where you are on the route and what's coming up ahead. Eventually it becomes second nature, and you make your way with less effort, allowing you to take on other tasks like taking a phone call (hands free) or listening to something interesting on the radio. This is an example of a larger area you know well enough to feel comfortable and navigate through with ease.
If you drive staring at the Sat Nav all the time, you will miss out on lots of the details of what is around you, and you will never really learn the route - you will instead be a slave to the Sat Nav and not able to do much more.
This same concept applies to us when making overhead dives - if we simply follow a line in and out of a cave, we are missing some of the most important things about the cave itself and probably also its natural beauty. I am not saying we should not have a line, but that if all we have is the line, then we are severely limiting our awareness and knowledge of the cave.
I first started cave diving in Mexico, and it was like being a kid in a candy shop - I wanted to taste everything and see all the caves I could.
With this “try everything” approach, you might go and make one dive in ten different caves and then go home feeling you had a great time and loved it all. The next time you go back, you don't really remember the caves as you only made that one dive before, and it's hard to keep them all straight in your mind. So, you make the same dive at the same cave not learning anything new and this type of "consumption" of many caves works against you - you never see more than the same part, and you never really take the details in or have them more firmly in your mind.
This is not the safest or best way to get the most out of each cave. Instead, pick a few sites, make several dives in a row at the same cave - learn the passages, memorise the details, the formations, look behind you at times and build that mental map of the place. Take a good look at a cave map before each dive and try to estimate where you will get to based on the profile (depths) and your gas consumption - see what is along the way and commit to memory some of the significant waypoints such as a noticeable change in depth or significant change in direction.
You should be able to know when these waypoints are coming, and they will provide a huge comfort on the exit when you find them in the reverse order coming out – especially if you looked behind you after passing these waypoints on the way in, so they are familiar to you on the way out. Challenge yourself after the dives to re-trace your route on the map and to find where your turn point was. As you gain this knowledge, you will become more comfortable, you will be more relaxed, you will see and enjoy more of the cave itself - you will become a more efficient and safer cave diver. When you are happy with where you are and feeling more comfortable, you will be in a much better mental state to handle anything that might come up and need some brain power for.
Get a feeling for the general direction on the way in - because guess what, you can expect it to be the opposite on the way out.
Another technique for not only relying on a line is the effective use of a compass. We don't necessarily need it to follow a precise bearing - but we can use it to know which way is home and where we might be on the mental map we have of a cave. For example, the caves on the East coast of Mexico (Riviera Maya) usually have flow running from North West to South East – but of course sometimes there is little or no flow and there is always the risk of a flow change. When you start your dive after deciding your route - straight away, you can verify if you are going up or down stream based on your compass showing mostly directions to the North or mostly to the South. You do not need to know an exact bearing, just that North or South are more often in the direction along the way. This is a very simple and reliable way to know if you are trending in the right way home.
As you study the cave map, look for significant changes in direction and note these new headings. By using the compass, you can be sure where on the (mental) map you are once you see this new direction - this can be more useful than relying on just your (variable) swim speed to estimate when you expected to reach this direction change waypoint. On Intro level dives, this becomes a handy backup tool to validate your exit direction if the spectre of doubt arises on the way out. For dives with complex navigation, it can be a big comfort when returning from a jump or T intersection to know you chose the right way home. For the cost of a few dozen plastic markers, a compass can sometimes offer more reliability!
Made It Home
If you do not know your gas consumption or your swimming speed, please don’t go into the cave and instead make a setup dive to get these vital pieces of information.
If you are not familiar with performing SAC calculations or reading cave maps, then please also take the time and training to find out.
Learn more about the cave and overheard training I offer here.
Take is easy, respect your limits and respect the cave 😊
If you have something to add, please leave a comment, and please share your experience if you've used any techniques for navigation.