3-Person Spiral Search

From TCEU

SPIRAL SEARCH Description The Spiral Pattern covers a small area quickly with a small number of divers.

The Spiral pattern uses one buoy and three divers. One diver, the Anchor, sits on the anchor and holds the end of the search line. Another diver, the Point or Tether, holds the search line reel and swims a circle around the anchor. The Anchor diver signals to the Point diver when he or she finishes the circle. The Point diver lets out enough search line to cover the visibility range and continues swimming, now covering a wider circle. The third diver, the Safety, stays at the surface. The safety diver keeps one hand on the anchor line for passing signals. Rope Pull Signals

The Spiral pattern uses the standard four rope-pull signals:

   * ONE pull: OK.
         o Always acknowledged with same signal.
   * TWO pulls: START or SLACK.
         o At the begining of the pattern the Anchor signals TWO PULLS 
           to tell the Point diver to Start the Search. 
         o During the search the Anchor signals TWO PULLS 
           to tell the Point diver when one circle has 
           been completed and it is time to let out more search line "SLACK". 
   * THREE pulls: STOP - Pull in search line.
         o The Anchor signals THREE PULLS to the Point to pull in the search 
           line and return to the anchor. 
   * FOUR pulls: FOUND - Come here.
         o The Point signals FOUR PULLS to the Anchor when he 
           or she finds the search target.
         o The Anchor signals FOUR PULLS to the Safety to come down 
           and assist when needed.
         o The Safety signals FOUR PULLS to the Anchor to stop the search.
   * CONTINUOUS pulls: HELP.
         o A diver who needs help PULLS REPEATEDLY on the Rope 
           to signal the others to come and help. 

JOB DESCRIPTIONS

ANCHOR:

  1. Hold the search line taut and up off the bottom.
  2. Signals to the POINT diver when the Point finishes one circle. 

POINT (or Tether):

  1. Hold the search line taut and keep swimming.
  2. When the Anchor signals "SLACK": let out enough line to cover the 
     visibility range, then continue searching.
  3. When you find the search target: signal "FOUND" to the Anchor. 

SAFETY:

  1. If Anchor requests help (with FOUR pulls on the anchor line): go down and assist.
  2. If the search commander wants the pattern stopped, signal FOUR pulls to the Anchor. 

Advantages: The Spiral pattern is good for rescue situations where you have a good starting location. It searches the area close to the anchor first, and it does not require any deployment time after the divers reach the bottom.

Disadvantages: The Spiral pattern is limited to about 30 feet of search line. With more search line out, the line drags on the bottom. The spiral pattern will not work well if there are obstructions on the bottom than can snag the search line.