Brushing Up on Underwater Navigation

underwater navigation

Diving around Maui for many years, we’ve come to know the underwater landscape and dive routes like the back of our water-soaked hand. But when diving in unfamiliar waters away from Hawaii, we rely more heavily on an essential piece of equipment—a dive compass. Of course we are not heads down looking at a compass when exploring reef architecture and marine life, but it is reassuring to have this handy way-finder to provide directions back to the starting point.

Good navigation skills can help prevent you from getting lost underwater. Of course, being aware of natural navigation, the physical contours and characteristics of the dive site, are essential too. Combining natural navigation with basic compass skills practically ensures you’ll never get lost underwater. Here are eight tips for improving your navigation skills on Maui, or where ever you are diving.

Listen to the briefing

Before you even get in the water, one of our dive masters, captain or instructor will fill you in on each dive site’s features, routes and what kind of marine life to keep an eye out for.  These guides are not only site experts, but will provide essential information on depth range, currents and conditions so you and your buddy can plan your dive. If you are shore diving, make sure to ask questions at our shop about the site, and discuss your dive plan with your buddy.

Start at the beginning

It’s a good idea to start your dive at the point where the boat connects to the bottom. Enter the water, throw us an ok topside, then start your descent with your group or buddy near the anchor line. Make note of natural references as you descend the dive site. Check your compass, and locate your dive leader.

If doing a drift dive with us, you won’t be navigating back to your starting point. Your dive leader will have a surface marker buoy, and so will you. You’ll be drifting with the current, and rendezvousing with the boat down current.

Follow the leader

While each diver is responsible for monitoring their air, buoyancy, time, depth and direction, our dive leader will navigate your dive. But it is good practice to take a compass heading once underwater, so you know the direction you are headed in case you should need to find your way back to the boat.

Pay attention

Even on a guided dive, make note of unique features or characteristics of the dive site that can make navigating back to the boat simple. Look for landmarks, such as unusual coral formations, sloped reef or a wall. Observing the sunlight angle at the beginning of your dive is also a natural directional clue.

Check in on Your Compass

We typically have clear conditions in our warm tropical waters that can lul a diver into a false sense of security. Even with great visibility, set and periodically check your compass. It’s not easy to find you way back by intuition if you lose eyesight of your Dive Master and the boat.

Always keep the long line on your compass, called the lubber line, pointed in the direction you want to go and your body pointed in the direction of the lubber line. The compass will work more efficiently if you hold it out in front of you in a flat horizonal position. This allows the wheel inside to spin freely. Rotate the bezel on top of the compass until the hatch marks meet the North arrow. When the compass is held in the correct position, the North arrow will always point to true North.

The reference marks on the rotating bezel make it easy to set your course. Rotate the bezel until the double hash marks are positioned on each side of the needle, while keeping the lubber line in the exact direction you plan to travel. To follow the course you’ve set, move in a direction that keeps the North needle between the reference marks. 

Take a reading by looking across the compass, keeping the device level. When swimming, wiggle the compass before reading it to make sure it is level. Then when you are ready to return, just make sure the north arrow points toward the marks on the other side of the bezel.

Other options

If you do lose sight of your buddy and Dive Master, and are in a relatively shallow site, you can make a safe ascent to the surface and get your bearings. Be aware when surfacing, listening for boat engines. Take a 360 degree look around, and locate the boat. You may want to give the crew the OK sign if in close proximity.

Further training

If you would like more information on underwater navigation, please contact our PADI 5-Star Dive Shop. We would be happy to answer your questions or provide information on the PADI Underwater Navigation course.

Once you master the concept, compass navigation becomes second nature, and is an essential part of safe diving.