This is part 6 of a 6 part series of articles on mastering the skills to become an expert diver. The earlier parts of the series are still available on SEAduction.com.
By Mike Ange Natural Navigation
Natural navigation is simply using physical landmarks as aids to tell you where you are. For example if you know your mooring line is tied a few feet aft of the bow of the shipwreck on the port side, when you reach the bow on the starboard side you should immediately know where to go to find your mooring line. In spite of what you may think, it is rare that the bottom of ocean or any other body of water is completely featureless. Even barren sand bottoms, typically have ripples which run parallel to the shore line or other features which denote the direction of the current or perhaps wave action. As much as all the coral reefs in an area may look the same at first glance, if you look at closer detail, you can nearly always find distinctive features that distinguish parts of a reef. The mistake most divers make is they identify these features and make note of how they look as they are swimming away from the exit point. Unfortunately, they may look very different from the other side when you are returning. So, as you swim away from the exit point, make note of a feature ahead, but then as you pass that feature, take a few seconds to glance back between your feet or over your shoulder to see what the feature will look like when you are returning to the exit point.
When you start your swim underwater you should also note the compass heading of the direction of your swim and note how that heading interacts with natural features. For example, are you swimming perpendicular to the ripples in the sand? Are you swimming along the edge of a drop off or sand shoot running for some distance along the coral reef? Perhaps you are swimming twenty or twenty-five degrees off that angle, the important thing is to note the general direction of your swim and the key landmarks that will guide you back to your exit point. Now you can enjoy your dive without focusing exclusively on the compass. Make it a point to check your compass whenever you check depth or tank pressure and learn to interpret those headings in conjunction with the bottom features. Try picturing a photograph of the bottom in your head and drawing lines in the directions you are swimming and you will always have some idea of where you are in relation to where you started. This will allow you to enjoy the scenery instead of watching your gauges – after all that is why you are diving, right? The landscape features will also help you to correct for minor variances in your compass headings and the effect that currents and surge may have on the direction that you are swimming. If you practice these skills by expanding the distance that you swim from the exit point in small increments over time, you will soon find that you always know where the boat is at the end of the dive. Well, almost always. When a free-swimming moray eel takes you off on an unexpected tangent, you might still lose your way. When that happens, you always have the option of swimming up and doing a “sneak peek” to shoot your heading back to the boat. Then you can submerge and use your precision compass skills to make it back to the anchor line. If you are quick and stealthy enough, no one will ever notice, and even if you are not, you will still look more professional than the guy flapping like a wounded albatross across the surface trying to make it home. Exits
Due to your excellent navigation skills, you and your buddy just surfaced next to the boat. The dive was great and you are feeling good. Now that the dive is over you can relax right? Wrong! First of all, the dive is not over until you are back on the boat with all of your gear stowed, and right now you are facing what can be the most challenging – and dangerous part of the dive. If the seas are calm getting on board is as simple as following the crews instructions, but there are some common mistakes that divers make. Even in calm seas, the boat moves and if you are caught in the wrong position it can smack you around pretty hard. Divers typically surface from a boat dive at the boat’s anchor line, at the bow, so your first challenge is to get to the stern platform. The expert diver will generally swim from the bow to the stern before they surface. If the current is slight to moderate and flowing along the length of the boat this is a simple process. Just complete your safety stop with the support of the anchor line and then swim or let the current carry you the length of the hull while you swim slowly to the surface. Time it so that you stay well below the keel or, better yet, slightly to the side of the boat and surface just behind the platform. But be careful not to get too far behind or you could find yourself struggling to get back. If the boat uses a trail or current line, it makes this process even easier, just surface between the boat and the end of the line, then grab on to wait your turn to board.
If conditions force you to surface at the anchor line, assess conditions before trying to swim to the stern. Assess the direction of the waves and surface current and swim along the lee side of the boat. so that the hull protects you from their impact. Swimming on the windward side means waves and current will push you into or under the hull. Be aware of the boat’s position and stay far enough away that you can respond should the boat begin swinging toward you, but stay close enough that you can easily reach the stern platform or current line.
When you reach the stern, wait your turn. If you never approach the ladder while another diver is still on the platform, you will never take a blow to the head from the other diver’s tank. Second, always remove your fins before boarding the ladder. Even with a fins-on boarding ladder, your exit will go and look smoother if you take off your fins before you exit. (NOTE: in really rough seas it may be safer to exit with your fins on if that is an option.) Make your exit a smooth process with this sequence: Approach the boat as the stern reaches the bottom of the swells or the trough. As you get close to the boat, deflate your BCD and keep your regulator firmly gripped in your mouth. Now grab the ladder and once you make contact never let go until you are on board. You will ride up and down with the ladder and the deflated BCD prevents you from having to fight the BCD’s buoyancy when the ladder bottoms out. It will also make it easier for you to drop away from the dangerous swing of the ladder should you lose your grip. Grab the ladder with your left hand and place your right leg firmly on the lowest rung. Brace against the ladder and bring your left ankle to your right knee – reversing the figure four process described in the section on entries – and remove your left fin with your right hand. DO NOT place the fin on the platform or hand it to a divemaster, use the strap to place the fin on your right wrist. This reduces the risk of losing your fin and in the event that you fall back into the water, you have your fins available for the swim back to the boat if necessary. Now reverse your position and remove the other fin using the same procedure. (In extremely bad seas you may choose to remove your fins while hanging on to the trail line. If you try this, stay far enough away that the movement of the boat cannot hit you but close enough that a couple of firm pulls on the line will take you to the ladder.) Keep all of your gear in place and time your steps with the movement of the boat as you climb the ladder. Keep moving. Do not stop at the top of the ladder to remove your mask or do anything else. You can do all of that in 10 seconds when you reach your seat. Once you remove your gear, strap it in before you do anything else. Don’t destroy a great exit by letting your gear crash to the boat deck with the first wave that comes along.
When your tank is bungeed in place – that’s when the dive is over. And when you have mastered each of the skills in this series of articles then you will not only look like an expert – but you will know that you have the skills necessary to truly enjoy your diving experiences.