Basic Search and Recovery
The first rule of search and recovery is to determine where the object went down, and start there. This is because in most situations, the object of search, whether, person, gun, boat or motor will be found in a radius equal to the depth of the water from the point it sunk. So if the exact point of a sinking object is known, then it can be found most rapidly. This is where good witnesses reduce search time.
Once decided on the area to be searched, the next step is to organize. Both orientation and visibility may be reduced, especially in freshwater. Nothing is more frustrating than losing tract of where you have been or where you are going. A basic plan is needed to prevent covering the same search area several times. Not all waters have ideal conditions for search operations. In fact most operations are conducted in low to zero visibility. Some lakes have plants such as hydrilla, a type of water grass that can be 40 feet in length. In the salt water environments it is the kelp that can appear as a forest under the sea. There are tree stumps, logs, and other various obstacles that can get in the divers way.
First the team must define the area to be searched. Signals must be established. Prior to any actual searches, a system to mark areas to be searched and those that have already been needs to be established. Every member of the team must carry marking buoys with him. They must mark objects found and prominent landmarks that could be used as rallying or reference points.
The type of situation dictates the type of search or rescue techniques to be used. Gather all information necessary and write everything down. Note where every witness was standing. Get the time the victim or object was discovered lost or missing, note the type of accident. If personal injury is involved get the victim’s age, race and physical condition. Where any vehicles involved? If so, how many people where on board, and note type and license number. Note the weather and water temperature. Gather information, talk to everyone involved with the lost object or person. Get bearings, landmarks, heading, speed, time, and tide. Visibility and depth. Type of bottom. Size of object. Note everything.
Silt is the biggest problem in search operations. Avoid contact with the bottom. Try not to use fins when close to or vertical to the bottom. Use anti-silting swim techniques, which is a more head down, feet up position. Proper BC control is imperative. Try not to let equipment drag the bottom, make sure equipment is secure close to the body.
There are several search patterns, so chose the one that is easiest to perform to accomplish the mission. When having to search around rock formation, coral heads, or wrecks, special problems will be encountered. They all have blind spots, over hangs, and all kinds of nooks and crannies. If the formations are small, the Team can start in one direction and search around the formation. When two teams are used they can go in opposite directions, and meet on the other side. After this, the search teams can start cress crossing the top of the object. For large formations the teams can use time to search a distance. Such as team one can search for two minutes along the bottom of the formation and then mark that location. Then go up a few feet and search two minutes back. Go up a few feet and search back to their marker line and so forth across the formation.
For a search operation to run smoothly there must only be one person in charge. This person in charge must be the member with the most experience in search and recovery operations. The activity must not jeopardize participants at anytime. Establishing ground rules during pre-planning guarantees safety. Decide on search patterns and define search area.
The Divemaster will be in the water to conduct any lifts that must be done. Every diver must know he is in charge once lift operations start. A Beachmaster is used to run the shore operation. A beachmaster is also a Divemaster but he does not enter the water, his job is to coordinate dive teams, search teams, back up divers and object removal from the water. It is an important safety feature that during search and recovery operations the team use two Divemasters. Do not have divers in the water without someone on shore keeping track of bottom time and position.
QUICK SEARCH is done by the first arriving divers. It is used when a victim went under close to shore or a pier and is very good at rapidly finding a victim. It can be a one man, or two man search. The two man quick search is the recommended one. However if speed is needed then the one man quick search can be very effective. The quick search uses the principle that a victim will be found in a radius equal to the depth of the water. When a victim falls off a pier or boat close to shore the first diver can start the search while other are arriving or getting ready. Equipment needed is the diver’s basic SCUBA gear and about 100 feet of line.
The two man quick search is performed by one team member getting the location and any other information, while the other diver is suiting up. Once the location is set the diver enters the water where directed by witnesses. The other diver assumes the role of tender. Once the diver reaches the point the victim was last seen he submerges to the bottom and starts to swim in an arc. The tender keeps the line taunt as the diver searches back and forth in a decreasing radius to shore or pier. The one man version is accomplished the same however, the searching diver ties his line off to a piling or tree before entering the water.
The search is effective because of the line that maintains the diver on a decreasing arc. Without the line the diver would have to use his compass and knowledge of the area and natural navigation to search, this slows things down. The search is also effective because it can be employed in less than two minutes after reaching the scene. The team should practice both the two man and one man using rescue dummies to see how effective this type of rapid search can be.
SNAG SEARCH is also a rapid quick search and is performed be one diver. The search is very effective for finding large objects quickly such as cars, boats or aircraft the enter the water. To execute the snag search a diver secures a line at a point he assumes the object went in. He then swims out past the location the object should be, taking all the line out, and descends. The diver then keeps the line tight and swims back to shore in an arc. Any object in the path of the line will be snagged be the line. If the diver gets to shore with the line, he can cross his anchor point, and pull the line in. If the object sought is in the movement of the line, it will be located, and divers can just follow the line down.
SPIRAL or CIRCULAR SEARCH can be done in low or high visibility. First the direction of search is determined before entering the water. A bottom marker is set to mark the center of the first area covered. A stake is placed to act as center point. The diver attaches his line to the center point. This line can be up to 100 feet in length. A starting and finishing line is run from the anchor out.
The divers align themselves on the rope with adequate amount of space between them, so that no area is overlooked. This spacing is dictated by two things, visibility and the size of the object being searched for. The divers begin to revolve around the anchor. As they go, line is played out and the circle gradually increases in size. This forms concentric circles in a very efficient pattern. Each time the starting line is reached one revolution is completed and a marker is set on the line, including a directional flag showing the next area to be searched. Once all the line is played out the search pattern starts again from the other end of the start-finish line. This type of search gives double coverage and is good in black water and for small objects. It works best with two divers.
CIRCULAR PIVOT SEARCH is done using a pivot method, by two divers connected by a piece of rope that governs the size of the circle. The size is based upon visibility, which can be from arms length to several feet. To accomplish the search the first diver acts as a pivot man and holds the line as the other diver searches in an arc using the rope as a guide. After the pivot man has made a complete revolution or 360o, he signals the searcher to stop. The roles are then reversed, with the searcher becoming the pivot man and the pivot man becoming the searcher. The sequence is continued for the desired length. This type of search can be very effective due to the fact that most of the area is checked twice, due to the overlapping circles.
SEMI-CIRCULAR SEARCH or FIGURE EIGHT SEARCHcan be done in low or high visibility. It is done normally by two divers at arms length apart for low visibility or further for better visibility. The divers are connected by a piece of rope. One diver acts as the pivot while the other diver searches in a circular motion. When the pivot diver turns a 180o or a one half revolution, he signals the searching diver to stop. He then becomes the searcher while the previous one becomes the pivot man. This sequence is continued until the desired length has been covered. This search pattern is very similar to the circular search and works well along walls, piers bulkheads or any areas where a full circular pattern will not work.
OUT AND BACK is a much faster and easier search. When visibility is good the pattern can be enlarged by using several divers on line. In low visibility the search should not be done by over four divers. Remember it is always better to have multiple search operations going on than to have a big mess underwater. To start the pattern all divers line up on shore and get a piece of rope that will connect them. Each diver places a butterfly knot or overhand loop at his point on the line to act as a hand hold. Distance between divers is governed by visibility. The loop in the rope should be large enough for the diver to slip his hand through so he can keep the rope on his wrist. One of the end divers is designated compass man and maintains the heading and distance. After the desired distance is covered, he signals down the line to stop. Remember all signals are passed down the line be every diver. After the search has stopped they reverse sides of the rope, and head back the way they came. The compass man just resets his compass 180o from his original heading to return. This insures the area is well covered, which is needed in low visibility water.
A variation of this is done when visibility is good. The search is done the same except once the desired length is reached the compass man signals to stop, and then takes a pivot position, turning the divers 180o. He then sets his back azimuth and signals the divers to start back. This covers twice the area as the standard out-and-back but should be done when visibility is better than 4 feet. The reason being that in lower visibility much can be missed. In zero visibility water it is often necessary to search crawling along the bottom felling your way. When this is done stay close and watch the rope, it may snag protruding objects. Remember to only use enough rope as necessary as it may entangle divers and snag objects.
When doing the out-and-back in poor or zero visibility water it may be necessary for the surface team to control the search. This is to prevent wondering due to the fact that the compass man cannot read his compass. To accomplish this the compass man takes down a guide line with him. The Tender then uses prearranged signals to keep the team straight, such as two left, three right. The tender sights down his compass and watches the diver as he tows a buoy. In strong currents, at night or in deep water the buoy will be deflected. At night this marker should have reflective strips on it and a chemical light tied to it. The tender then sights on the marker. Before the dive, remind the diver with the marker, to keep the line tight. Another type of guide line is having a diver surface swim out about 100 feet of line and then descend and anchor it to the bottom. He then surfaces and returns to shore. This line can now be used by the compass man by running his hand along the guide to stay straight.
PARALLEL SEARCH works well as a quick search from a shore line. The direction of the search is decided prior to entering the water. A maximum depth and time should be set also before the dive. To begin a line is extended to accommodate all the working divers. Length is limited to allow an adequate distance between divers and is dictated by visibility. After being set on the line each diver places an overhand loop or butterfly knot, in the line to mark his spot in the search.
To begin the rope is played out perpendicular to the shore. As the divers move forward they conduct a search parallel to the shore line. The line is kept taunt and a straight line is maintained. This is best done by a diver on the shore holding one end of the search line and walking down the shore as the divers search. This way the diver on the shore can act as a guide for all the others and ensure a straight search. Additionally the diver farthest from the shore must tow a buoy so surface personnel can see the contour of the search line. The buoy also will alert boating traffic to the dive operation.
As with the out and back search, the parallel search is best done with a limited number of divers. A good rule of search patterns is that as the number of divers conducting a search increases the chances of fouling lines and screwing up, also increases.
GRID SEARCH is the most accurate type of search to use, it is also the most time consuming. It is a complicated search method that is hard to employ and requires experienced divers with lots of training in its procedures. The grid is rarely used by dive rescue teams. However if the team is looking for small objects it is the best search to use. It also teaches divers team work and search procedures, so makes an excellent training dive. Never use a grid search in the rescue mode, it is never indicated and should never be considered.
To conduct the search squares are marked off with marker buoys that are stuck into the bottom, such as coat hanger flags. These squares are then searched by one or two divers. Each grid area is given a designated number. All markers are given the same beginning number. As an entire square is searched anything found is marked with a surface marker. When the square is completed the divers return to report and log what they found. No fins should be worn in the search area.
PIVOT BOARD SEARCH: Briefly described the pivot board is made of a steel plate, to which a piece of pipe is welded, sticking up, with an eye bolt on top. The diver wishing to search an area with it lowers the board and attaches a line to the eye bolt. He can then do circular or sweep searches; using the board as an anchoring point. Pivot boards have always been cumbersome, heavy and in some cases exhausting to employ. Due to their weight and size, they are never where you are when you need one. In rapid response rescue, time is of utmost importance. A quick deployment search device that mimics the pivot board in use, but can be carried in your dive bag is discussed next.
After every search it is very important that the team log in all recoveries, noting where they where found. The type of search performed should be drawn out on a map. A partial map of the area can be used as the final record. Proper use of the information will be valuable in the future. Recording should be assigned to one person. This will allow for consistent drawings and diagrams. Accurate dimensions and distances will keep everything straight. Random drawings made by several divers creates confusion.
Accurate records must be kept. This consist of plotting work and photographs if taken. All information possible is helpful. Each buoy has a number as recoveries are made the spot marking where the object was found is recorded. Line of sight references can be made from shore to the buoy as well as compass headings Masking tape can be used to record on the object where it was found Information is put down as to where it was found, by whom, date, team, buoy number anything that makes it easy to recall.
For photos any camera will do. To identify the item place a white card with a black number code next to the item. This number shows in the picture and should correspond to the codes in the log and markers.