NAUI Master Scuba Diver 220 Search and Light Salvage conditions is generally a justifiable task that, if properly done, involves minimal risk. On the other hand, searching for a pair of sunglasses dropped from a pleasure boat in a dirty harbor (where the water may be polluted) places the diver at an unacceptable level of risk. The sunglasses are not worth contracting a disease. Unfortunately, many divers do not even consider the potential health hazards associated with rivers and harbors in such places. Risk-benefit assessment requires that the diver examine the environment, circumstances, worth of the object, skill, equipment availability, personal training, prior experience, and many other factors. Laws and Regulations Even though a vessel is sunk, abandoned, a derelict, or aground, it and its cargo belong to the owners of the vessel. In many cases, it may be the property of an insurance company. Salvers must obtain permission to salvage the vessel and they must adhere to laws and government regulations. In some situations, major consideration must be given to the potential for environmental impact. Keep in mind that many objects are protected under various laws intended to preserve items of historical significance. Whatever is salvaged must be documented with an admiralty court. State, federal, and foreign governments may also have claims whenever an object or vessel falls within their jurisdiction. Search Procedures One capable person needs to be in charge of a search operation. Everyone involved must agree to follow the instructions of the search leader. Establish depth and time limits for the search and salvage operations. Discuss and agree on emergency procedures for accidents that may occur during the diving operations. Next, select and practice the search pattern planned to be used underwater. Be prepared to mark the location of an object when it has been located. An item can become quickly lost again after it has been found if the location is not marked. A diver-deployed buoy can be attached to an item under water and released to float to the surface. FIGURE 9-1. CONTOUR SEARCH PATTERN. Everything possible must be done to avoid disturbing the bottom and stirring up silt. Do not wade around in the water. Avoid finning near the bottom. Use slight buoyancy to ascend rather than swimming upward from the bottom. Avoid contact with the bottom as much as possible. Slight buoyancy that requires you to swim with your fins slightly above a horizontal plane is desirable. SEARCH PATTERNS To select a search pattern, consider the number of searchers available, their training and experience, the available equipment, the water and bottom conditions, the above-water conditions, and the weather forecast. An underwater search is usually conducted by swimming a definite pattern. The two fundamental types of search patterns are straight line and circular. All accepted search patterns are simply variations of these two basic themes. Different patterns lend themselves better to one type of search than others, depending on the type of bottom, depth, obstructions, and the base of operations. Several search patterns will be described. An imaginative combination of two or more of these basic patterns will usually prove effective in almost any instance. All search patterns involve distance measuring. This can be accomplished by using measured lines, by count-
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