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The Search and Recovery Environment. In many types of diving, you chose the diving environment, but in search and recovery, the environment often chooses you. That is, you don’t decide where someone loses something, and sometimes the only reason you’d dive in a particular area is to search for and recover something lost there.
Besides dictating where you dive, the environment’s bottom topography – its contour, shape, obstructions and composition – dictates the search technique you use. For instance, a flat, open bottom allows you to use ropes and scan large areas quickly, but also makes it easier for water flow to move the object. By contrast, an irregular, obstructed bottom is more difficult to search, but more likely to keep the search object from being swept away. These call for differing search techniques.
Water movement affects search and recovery more than by moving the object. Tides, surge and currents can bury an object and interfere in your search by making it hard to maintain an accurate search pattern. Water movement can also help. In a current, for example, you can fan away silt and dirt, letting the water carry it away as you work.
Environment will also affect visibility, whether you have boat traffic to contend with, and potential hazards you need to avoid. If you’re unfamiliar with the environment, if possible, get an area orientation from a diver experienced with diving there. You might want to make some an acclimation dives before beginning a search. Potential Hazards.Search and recovery sometimes takes you into some unusual dive environments, so you face potential hazards that don’t exist, or are not as common with other types of diving. Once you’re aware of them, none are particularly extreme or difficult to avoid, provided you stay alert. Sharp Objects and Debris.
If you’re looking for something small, you may grope around a bit on non-sensitive bottom. But, that’s where mud and silt can hide broken glass, wire, rusted metal and other sharp objects that can cut the unwary diver. When swimming close to the bottom, or pulling yourself along, or in poor visibility, always wear an exposure suit and heavy-duty gloves for protection. Watch where you put your hands, feet, and knees and move cautiously. It’s not a bad precaution to keep your tetanus immunizations current, too. Entanglement. Some search and some recovery techniques involve ropes, and when you have rope, you have potential entanglement. Handle lines carefully and store slack on a reel. Around piers and when diving on irregular bottoms, watch for monofilament line and fishing nets that can also cause entanglement. Carry a sharp dive knife or dive tool as a precaution against severe entanglement. Low Visibility.If the water were air-clear, chances are you wouldn’t need a search to find what you lost. Less-than-ideal visibility goes hand-in-hand with search and recovery most of the time, which can add stress caused by disorientation and buddy separation. If the viz is too poor for your comfort, don’t dive – remember, this is supposed to be a fun challenge. If you dive, take care not to kick up the bottom and make the visibility worse, and pay close attention to navigation and buddy contact. A short line between you and your buddy may help you stay together. Currents.The concern with currents is being swept away from the dive boat, your exit or the search area. Plan the dive with the currents in mind, consulting local dive professionals or divers about them if you’re not familiar with the environment. Try to search into the current away from your exit point and be prepared to abort your dive if it’s stronger than anticipated. When searching rivers and other environments where strong currents are inevitable, use the search techniques developed for currents. If a current is so strong as to present an unreasonable hazard, leave searches in that environment to professionals. Sinking Recovered Objects.When recovering an object with a lift bag, a poorly tied knot or improper lifting poses a hazard if what you’re recovering slips and sinks. Not good. During your Search and Recovery Adventure Dive, you’ll practice recovering objects using techniques that make dropping the recovered object unlikely. And, assuming your best intentions go awry, you’ll also learn how to be out of an objects way if it does sink back to the bottom.
Boat Traffic.Since you count on boaters to drop things overboard from time to time, it follows that search and recovery frequently takes place near boat traffic. To minimize boat hazard, mark your position with a locally recognized dive flag, and preferably, mark off your entire search position (if you can do so without obstructing the traffic) with dive flags. If possible, have someone at the surface to watch and warn off boats encroaching on the search area. PADI 5 Star National Geographic Instructor Development Center. 198/12 Rat-U-Thit Road, Patong, Phuket, Thailand. Phone: (+66) 076292052 Fax: (+66) 076293034
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