Returning to shore or one’s boat while underwater is more than the mark of a skilled diver. It can save you from tiring surface swims and prevent accidents. Being able to return to your starting point while still submerged minimizes the possibility of being struck by an inattentive pleasure boater when diving in busy waters. Marking your dive site with a surface float and diver down flag like the ScubaMax Floating Ball and Flag Holder, that is found on Scuba.com, is required by law in some dive locations, but it has little practical benefit at the end of your dive if you surface two hundred yards away. Surfacing down current from a charter boat can be downright embarrassing if you have to call for help or a pick up. However, to the new diver, the underwater landscape can appear so homogenous that orientation is quickly lost and the dive float or boat might as well be on another planet. So how do experienced divers do that? That is, surface right at the dive platform. Navigating underwater is a thinking exercise that requires a little attention, the right equipment and some practice. You can excel at this skill and master it even more quickly by taking advantage of the following hints.
The best acquisition you can make that will assist you in scuba navigating is an underwater compass. Serveral types and styles like the Sherwood Retractable Compass can be found at Scuba.com. And the best advice for its use is to trust its sense of direction over your own. Without a compass, or if it is damaged and quits working during a dive, you’ll have to completely rely on your ability to use naturally occurring phenomena (sand ripples, wave surge, etc.) and dead reckoning to establish your position.
Regardless of navigation method, you need to tune in to your surroundings. Take an initial step toward improving your navigating skills by practicing what scuba instructors refer to as “global awareness.” Global awareness describes a conscious effort to heighten your awareness—to see and record your immediate environment.
Remember the old “being a witness” exercise from school? After viewing a film or video replay of a reenacted crime, participants were asked to describe the perpetrator and provide such details as hair color, height, weight, clothing color and style, etc. Usually, very few casual observers could accurately recall any such details, while trained law enforcement individuals can accurately recall virtually the entire scene. If the exercise continued, the next step was to demonstrate how easy it was to increase one’s powers of observation and recall. The most important element was being ready to observe, to see and record your surroundings.
As a diver, being ready to observe begins before you enter the water. Look closely at the shoreline. The landscape that you see on shore usually continues underwater. Also, mentally recording what the shoreline looks like can help you return to your starting point if you need to “cheat” and surface for a quick peek and to reference a landmark. Take note of the sun’s position in the sky. Is it coming over your left shoulder when you face the water? If so, this is where it will shine when you are traveling away from shore.
If you surface swim away from your water entry point, whether shore or boat, periodically look back to fix an image of what your return path will look like. Taking a range or fixing your position prior to your initial descent, while it won’t have a significant impact on your underwater navigation, is also a good habit to develop. Establishing a range is simply identifying two in-line objects that provide you with a line of position. This is an imaginary line that you draw through the two objects and extend to yourself. With a compass you can take a bearing to establish the heading to travel on that same line of position. To obtain a fix, turn 60 degrees or so and establish another range—your position fix is where the two lines of position intersect. If you intend to descend directly under the dive boat you can fix your position from the deck before you enter the water.
As you make your initial descent, face a particular direction. Any direction will do; you can face shore or your anchored boat. The objective is to avoid turning around and around losing your sense of direction. In this way you can begin your dive in a direction that is relative to the shore or boat’s position, that is, parallel or perpendicular to your starting/ending point.
Once you reach your diving depth, take a moment to observe your surroundings. Take note of any distinctive topographical features within the range of visibility. Fix their locations in your mind relative to your previous observations. If you’re wearing a compass, sight a bearing leading away from your starting point, and write down the reciprocal heading on a slate. If you’re not using a compass, pick a landmark and swim to it. From there choose another and so on. At the halfway point of your air supply you can return from landmark to landmark until you reach your starting point. Most of the time, knowing where you are results from remembering where you’ve been.
Distinctive underwater landmarks eventually reveal themselves to even the most casual observer, especially after repeated dives in particular locations, but dives are more enjoyable in all locations, whether new or old, if the foremost question in your mind isn’t “Where am I?” Get yourself a good underwater compass and practice raising your awareness of your surroundings. Diving’s more fun that way.
Jed Livingstone is vice president of NAUI Worldwide.