Dive professionals are often asked how they found the boat at the end of the dive. Underwater navigation, though mystifying to some, shares the same principles as land-based orientation. Similar to finding your way around an unfamiliar town, recognizing landmarks and your surroundings is crucial for navigating underwater. Unlike land, you can't ask people for directions underwater, so we rely on a compass. While a compass proves invaluable at unfamiliar dive sites, returning repeatedly to the same site allows you to identify familiar reef sections and build a mental map, ultimately relying more on natural navigation to find your way. If you've been struggling to keep track of where you are on a dive, here are a few tips on how to navigate underwater to help you stay relaxed and on course.
Natural Navigation
In our daily lives, we use natural navigation without realizing it. When seeking directions in an unfamiliar town, people refer to buildings (often the pubs!) and natural features to guide us, similar to how dive professionals navigate underwater. While divers add depth to their directions, the process closely resembles finding your way around on land.
Dive certification courses often emphasize the dive compass, but mastering natural navigation is the best way to avoid getting lost. The drawback is that you need multiple dives at the same site to gain a deep understanding of the topography.
When diving with a guide, navigation is less critical, but it can become invaluable if you become separated from the group.
Natural Navigation Cues
If you do come separated from your dive group, there are several cues that can assist you. First, keep an eye on the depth, as boats often anchor in shallower sections. Current direction can also guide you. If you started against the current, turning your back to it should lead you back to your starting point. However, be aware that currents can change...
Also, keep an eye out for the plant and coral life. If you swam past a bright red sea fan at 12 metres at the beginning of your dive, returning towards the boat at the same depth should allow you to locate that same sea fan. Finally, the sun's position and its shadows can also indicate direction. On morning dives, the sun will be positioned towards the east, and it will shift to the west for afternoon dives. From there you can establish which direction is north.
Insider tip: Always check the depth below the boat at the start of your dive and pick a recognizable coral or rock formation to make finding the boat easier later.
Compass Use
Natural navigation may be king when it comes to finding your way around a dive site, but always carry a compass, especially when not guided, exploring unfamiliar sites or night diving. Underwater compasses may seem intimidating but keeping it simple is key. A quick glance at your compass will help orientate you if you get lost from your group. To hone your navigation skills, study the dive site map before diving and pay attention to the map's north arrow.
Measuring Distances
Measuring distance is often seen as a key part of learning how to navigate underwater. Unless you are conducting underwater surveys or archaeological dives, you probably won't need to measure any exact distances. That being said, it's good to time the dive so you can reach your safety stop at the correct time.
Ensure you have a way to track time, such as a watch or dive computer. For out-and-back dives within an hour, head out from the boat and turn back at around 25-30 minutes. For shorter distances, count your kick cycles. A typical fin-kick is about one metre.
Staying Safe
While striving to become a more self-sufficient diver is commendable, don't push your limits too far. If you want to learn how to navigate underwater, seek guidance from dive staff. Some sites are easier to navigate than others, so don't rush your progress. Shallow coral gardens are great for practice, especially in resorts with house reefs. Remember the 'one-minute rule' for missing diver situations: if separated from the group, your guide may surface after one minute, expecting you to do the same. But if you have decided to try to navigate your own way back to the boat, your guide's heart rate will quicken if you don't surface within the prescribed one minute...
