Knowing your location is a key to safety when diving. You do not want to surface in an unsafe area (like a busier section of water with more boats. You do not want to surface too far from your boat or from the shore. If you’re shore diving, for the last dive of the day, it’s annoying to end up too far from your dive flag and having to swim to it, then drop down again to retrieve it so you can pack up and head home.
The Course
I took the SSI Navigation and Limited Visibility course with Jared at Diventures. Dave (who has since become an instructor) was an assistant instructor at the time, helping with the class. This was key because Dave has extensive experience on land with a compass, and it translated well to his instruction, helping with the learning process of navigation. We practiced navigating in the parking lot of the dive shop with a blanket over our heads, so we couldn’t see any landmarks and had to rely on the compass. It was a great way to get comfortable with compass navigation.
The required dive skills included navigating a course by finding each point using compass headings alone. When Jared took me on that part of the course, I was able to hit each spot directly, which was surprising to me because the visibility in the lake that day was not ideal. That brings up a great advantage of knowing your compass skills. You can navigate safely in less-than-perfect visibility.
Similarities to Land Navigation
Navigating underwater is one of the skills that is not significantly different than navigating on land. A compass still works the same. Natural navigation is still possible, that is, navigating by familiar terrain and landmarks. You can even take a map with you, either sketched out on a slate or in wetnotes.
Differences from Land Navigation
A few of the differences are not things you’d typically think about. GPS does not work at all. The GPS signal is generated by satellites, but it’s not a particularly strong signal. As a result, it will not penetrate underwater. GPS only works on the surface, so it is not a helpful navigation tool once you are submerged.
Compasses work by magnetism. A magnetic field from something other than the planetary poles can impact the accuracy of the compass. For example, a large shipwreck full of steel can do it if the metal has any magnetic field about it. I discovered that proximity to a power-generating dam can do it if you’re too close. It isn’t reassuring when you’re practicing with a compass and the needle jumps in a 60–80-degree arc due to an interfering magnetic field.
Task Loading and Safety
In scuba diving, task loading refers to the combined physical, mental, and environmental demands placed on a diver during a dive. When these demands exceed the diver’s capacity, safety can be compromised. Managing task loading is critical underwater, where distractions or excessive responsibilities can cause divers to lose track of essential safety checks such as monitoring air supply, depth, or buddy location.
Excessive task loading underwater can lead to cognitive overload, which reduces situational awareness and slows reaction times. Physically, divers may experience fatigue from handling equipment or navigating environmental challenges, such as currents. At the same time, mental strain from tasks like navigation, photography, or complex dive plans can cause them to neglect core safety practices. In addition, on deeper dives, cognitive strain is increased due to the effects of nitrogen narcosis, increasing the risk.
To mitigate these risks, do not add new skills until you have mastered previous skills. Plan your dives, even simple ones. Know your equipment and don’t add a lot more all at once. Practice regularly so tasks become automatic. This will minimize the risk of a series of simple tasks from overloading your ability to think and keep you and your buddy safer. Analysis of diving accidents shows that task loading is consistently a factor.
Task Loading and Navigation
What does this mean for navigation skills? It means to practice them frequently. Practice on land until you become familiar with using your compass. Practice natural navigation on every dive, even well-known dive sites. Make both natural navigation and compass navigation second nature or automatic. If you do this, it will minimize the load that particular task places on you. Make it a personal challenge on each dive.
My Navigation Skills
They were not great. I struggled with my compass at first. I misread many of the natural navigation cues at dive sites I frequently visited. But after a lot of practice, it started to click.
A wreck that I could never find is one that I can now go straight to. There are some dive sites where I can see a natural landmark and know which direction to follow on my compass from that natural landmark to get to where I want to be. I’ve even been able to help direct new divers on the site on how to find their way around.
All it takes is practice. The great part about practicing navigation skills in diving is that you’re diving. It’s fun. And the better you get at it, the more fun it becomes. Most importantly, the better you become at it, the safer you will be.
