Chapter 15: Search Operations



o       Checking in at the incident (p. 254)

o       Crew mission briefing (p. 254)

o       Crew mission debriefing (p. 255)

o       Checking out of the incident (p. 256)

o       Containment (confinement) (p. 242)

o       Hasty search (p. 242-245)

o       Loose grid (p. 243-245)

o       Tight grid (p. 245-247)

o       Evidence search (p. 247)

o       Base line (p. 243)

o       Guide line (p. 243)

o       Guide person (p. 243)

o       Search lane (p. 243)


I. Resources

PowerPoint slides, Chapter 15, LPQ, LCD projector


II. Teaching Points


A. Tactics  (p. 240)

  1. All techniques employed to actually find a lost subject or clues
    1. Usually applied by the search manager immediately following first notice
    2. Usually involve a definite progression of techniques
    3. Generally fall into one of two classes:

i.                     Indirect

ii.                   Direct


  1. Indirect tactics
    1. Almost always the first to be employed, particularly with regard to fact finding or information gathering
    2. Fact finding

i.                     Collecting any information that can help focus or resolve the search.

    1. Attraction

i.                     Efforts taken to cause the subject to be attracted to, and travel to, a desired location.

ii.                   Assumes a mobile and responsive subject.

    1. Containment

i.                     Efforts taken to confine the movement of a lost subject to minimize search area

ii.                   Includes route blocks, lookouts, track traps, patrols, and attractions


  1. Direct tactics
    1. Include all organized methods used in the search area to detect a lost subject or clues.
    2. Generally, three types of searches:

i.                     Hasty searches

ii.                   Loose grid searches

iii.                  Tight grid searches


  1. Hasty search (non-area search)
    1. Fast initial response of well trained, self-sufficient, and very mobile searchers who check places most likely to produce clues or the subject quickly
    2. Techniques used to accomplish hasty searches include:

i.                     Thorough check of last known position (LKP) or point last seen (PLS) for clues, track, direction of travel

ii.                   Following known or suspected route

iii.                  Perimeter check

iv.                 Sign cutting all around a piece of evidence, abandoned vehicle, PLS, or LKP

v.                   Checking of hazards, attractions, drainages, buildings, trail, roads, and any other places where subject or evidence is likely to be discovered quickly

    1. Hasty teams are usually made up of two to four searchers.
    2. Must be prepared to conduct effective searches.
    3. Generally used during the early stages, but can be used at anytime



B. Some grid search definitions (p. 243)

1.      Base line¾A line, perpendicular to the direction of travel, on which the searchers line up

2.      Guide line¾Otherwise referred to as the control line; the direction in which a searcher looks for guidance as to the status of the search line

3.      Guide person¾The person who guides the search team. Always found at the end of the base line unless the guide is toward the center, then the guide is center of the base line.

4.      Search Lane¾The area an individual searcher is assigned to scan

5.      Trail Tape/Ribbon/String¾Material that can be used to indicate a line where no natural line exists


C. Area searches (p. 243)

1.      When hasty searches alone do not resolve the search, expansion into “area searches” may be required.

2.      In an area search:

a.       A segment of the search area is searched in an organized manner by a specific resource.

b.      The segment must have clearly defined boundaries that are identifiable on a map as well as in the field.

c.       Organize the searchers in some type of line or grid.

    1. Two methods of forming the line:

i.                     Tight grid search

ii.                   Loose grid search

    1. Both types of area search tactics use lanes, but they are scanned or covered in different ways.


D. Loose grid search (area search) (p. 243)

1.      Can consist of three to seven people, but usually just three because of the ease of team coordination

2.      The goal of this technique is cover large geographic areas quickly and with fewer resources.

3.      The trade-off is lower overall coverage (less thorough).

4.      The benefit is that it allows some reasonable level of coverage to be spread over a large area in a relatively short time.

5.      A team conducting a loose grid search would organize on a base line (usually at wide between searcher spacing) and proceed forward.

6.      Spacing searchers is dependent on terrain and visibility.

7.      The amount of overlapping area scanned by both searchers in adjacent search lanes should be minimal.

8.      The amount of area between adjacent search lanes that is scanned by neither searcher should likewise be minimal.

9.      As a rough guide, this can be achieved in the field by spacing searchers at a distance greater than the established average maximum detection range (AMDR) for the environment being searched.

10.  It’s best if members can keep occasional visual and voice contact.

11.  Once the baseline and guide for the search is established, the segment is divided into an appropriate number of search lanes based on

a.       The number of searchers

b.      Search speed (affected by terrain and vegetation)

c.       The amount of time assigned for the task (usually less than 6 hours)

d.      The size of the segment

12.  The goal of the team should be to finish their assigned task in the time allotted.

13.  Thoroughness is not a characteristic of a loose grid search.

14.  Loose grid search has a number of important characteristics:

a.       More flexible and requires much less coordination of individual searcher efforts than tight grid searching

b.      Search lanes are relatively wide, often much wider than the average maximum detection range of the search object(s).

c.       Searchers can adjust and tailor their movements to the environment, thereby making more efficient use of their time and effort.

d.      It can be used in situations where more thorough search methods are difficult or impractical.

e.       Loose grid searches are generally less damaging to the environment and any evidence not found during the search than more thorough techniques.

f.        With trained, skilled, experienced searchers it generally takes less time to achieve a reasonable coverage than more thorough search methods.

g.       The overall probability of success for the search effort as a whole can be increased more quickly with this technique.

h.       Loose grid searches are often employed after hasty searches, especially if hasty searches found clues.

i.         This type of search should be used when subject responsiveness is assumed to be high.

j.        With appropriately skilled and alert searchers, this type of search may also locate clues


15.  Techniques used to accomplish loose grid searches include:

a.       Relatively wide spacing between the centers of adjacent search lanes

b.      Compass bearings or specific guides are often used to control search direction toward the opposite side of their assigned segment

c.       Searchers can quickly move back and forth laterally while maintaining a net direction of movement across the segment

d.      Often applied in a specifically defined area or segment of the search area to follow up where a clue has been found or to cover segments indicated by clues found elsewhere


16.  In the past, loose grid searches also have been referred to as open grid, “Type II”, and “critical separation”

17.  Sound sweeps:  a coordinated effort to attract a responsive subject


E. Tight grid search (area search) (p. 245)

  1. This type of search is a slow, highly systematic area search. I
  2. Generally used when a very thorough, high coverage search of a segment is desired
  3. Best suited for higher coverage searches
  4. Techniques used to accomplish tight grid searches include:

a.       Searchers line up on a baseline, usually at relatively close spacing.

b.      They then proceed along straight, parallel, equally spaced tracks¾to the extent the terrain and vegetation allow.


  1. A typical tight grid search might achieve a coverage between 1.0 and 2.0 (probability of detection between 63% and 86%).
  2. The criterion for tight grid searching is generally thoroughness in a specific segment as opposed to rapid increase of overall POD.
  3. The main objective of a thorough search is to minimize the chances that a clue will remain undetected.


E. Evidence search (p. 247)

1.      SAR teams are sometimes called upon to perform evidence searches, often at a crime scene.

2.      This type of search is a more thorough variation of the tight grid search.

3.      There are three differences between a tight grid search in SAR and an evidence search:

a.       Evidence searches do not involve a live subject.

b.      Evidence searches often involve looking for small objects in limited areas.

c.       The rules of evidence (such as maintaining chain of evidence, protection of the evidence, recording the evidence as it is found) will strictly be enforced on evidence searches.

4.      Important characteristics of an evidence search include:

a.       Time is not usually as important.

b.      Often there will be no second chance. Evidence not discovered on the first search may be destroyed.

c.       Large amounts of effort must be concentrated in small areas to achieve high coverages for even very small objects (hands and knees).

d.      It is very important that each object found be left in place untouched and undisturbed by the searcher.

5.      Evidence searches have also been referred to as “Type IV” searches (“types” now conflict with the NIMS resource typing system).


F. Information to report to planners after a search (p. 248)

1.      Several important pieces of information that affect search planning should be conveyed to search planners by field personnel after an area search is conducted:

a.       Estimated forward search speed of the individual or team while searching

b.      How long the individuals or team searched

c.       Field measurements of average maximum detection range (AMDR) or some similar field observable measure

d.      Other field-observable measures identified and requested by search planners prior to the assignment

e.       A qualitative description of how well the team did with the search

f.        A qualitative description of the search conditions


G. Forward search speed (p. 248)

1.      An estimate of the average search speed is needed so the effort, or total distance traveled while searching, may be computed by search planners.

2.      One way to estimate forward search speed is to first measure search speeds during SAR exercises or on actual searches to determine the “normal” speed for you and your team.

3.      Using this measure as a reference, searchers then can describe their forward speed in comparison as either slow, normal, or fast.

4.      Values could then be assigned to each of these speed categories (e.g., slow = 0.5 ´ normal search speed, normal = 1 ´ normal search speed, and fast 1.5 ´ normal search speed)


H. Time spent searching (p. 248)

1.      If search planners know how fast searchers are traveling (V) and exactly how long they have been searching (t), the “track line length” (TLL) can be computed:

                                                Track Line Length = V ´ t = TLL

2.      This value is very important to search planners, as they need to eventually compute POD.



I. Average maximum detection range and other field-observable measures (p. 248)

  1. The concept of sweep width (Ch. 14) as a key element of search theory has been in use in SAR for over 50 years.
  2. Table of sweep width values for searches can be found in the International Aeronautical and Maritime Search and Rescue Manual (IAMSAR Manual, 1999).
  3. AMDR can be estimated in the environment in which the search will be conducted, using a search object representative of that which is being sought.
  4. Other writers have called it the “visibility petal” and the “rain dance,” but it is the same thing: a field measurement of the AMDR.
  5. To measure the AMDR:
    1. Place an object (similar to the search object) at a location to be judged to representative of the conditions in the search area as a whole, usually in the segment to be searched.
    2. Beginning at the object, walk away from the object until it is no longer visible.
    3. Keep track of the number of paces of known length (tally) and use these to estimate the distance.
    4. Note or record the distance to this point.
    5. Continue away from the object for another 50 to 100 meters.
    6. Travel clockwise around the object about 45 degrees and move toward the object until it is sighted again.
    7. Record the distance from this point to the object by counting the paces to the object from the point of sighting while returning to it along a straight line.
    8. Then move away from the object at 90 degrees to the right of the initial departure, which should be about 45 degrees from the direction of approach just used.
    9. Again, measure the distance to the point at which the object disappears.
    10. Repeat this sequence until eight (or so) detection distances are established.
  6. AMDR measurement process performs several important functions:
    1. It gives searchers the experience of seeing how an object similar to the search object appears in the environment where the search is to take place.
    2. Although AMDR, strictly speaking, is not a measure of detectability, it does give the search planner one quantitative measure of what search conditions were like.
    3. Having had the experience of performing an AMDR measurement, searchers may be in a better position to make other observations about their environment and search conditions.


J. Qualitative description of completed search (p. 250)

  1. Fatigue, exhaustion, injuries, and other distractions that may not influence the field estimate of AMDR can reduce the effectiveness of a search crew during operations.
  2. All details related to the conduct and effectiveness of the search should be provided during the debriefing. These may include:
    1. The crew felt rushed or hurried.
    2. The size of, or the terrain in, the assigned segment caused the crew to go faster or

      slower than normal search speed for the conditions in the segment.

    1. Prejudice
    2. Fatigue or exhaustion
    3. Searcher boredom or other preoccupation
    4. Anything that detrimentally affects any senses of the searcher
    5. Non-uniform coverage
    6. Conditions were different from those described in the pre-search briefing.


K. Grid naming (p. 250)

  1. Developed by Explorer Search and Rescue (now called Venturing) teams in the Pacific Northwest to describe any specific grid (area) search pattern
  2. The system consist of a number-word-number sequence that serves as the name of the pattern.
  3. Example:          6 – guide   [right] – 30

a.              The first number describes the number of searchers on the grid or control line (6 searchers).

b.              The team leader is not included in this number if he/she is working behind the line.

c.              The word is either “compass” or “guide” and indicates what the team is using as the guide. (The example describes 6 searchers on the guide line, guiding right, with an average between searcher distance of 30 feet)


  1. This grid naming system has several advantages:

a.              It offers an easily recognized method of communicating the details of a search pattern so that the search management team and the field search team can ensure mutual understanding.

Allows an opportunity to estimate a search team’s base line width.






L. Guidelines for skilled searching (p. 251)

1.      Experienced SAR personnel have developed certain practical techniques and guidelines.

a.       Stay alert and maintain a proper attitude for effective searching.

b.      Use all of your senses for searching.

c.       Scan the “searcher cube” while searching and while approaching the search area.

d.      Yell and make noise occasionally and intermix regular moments of silence.

e.       Always take the Boy Scout Motto to heart and “be prepared.”

f.        Learn the names of the searchers on either side of you in a line search.

g.       At night, never shine your flashlight or headlamp into your eyes or those of other searchers.

h.       Always check the obvious.

i.         Do not talk with the family of the subject or the media unless assigned to do so.

j.        Search for clues as well as the subject.

k.      The safety of the searchers is more important than the mission itself.



M. Anatomy of a SAR incident (p. 252)

  1. Preplanning and preparation
  2. Equipment
  3. Self
  4. First notice
  5. Notice of incident
  6. Personnel call-out
  7. Check-in
  8. Briefing
  9. Assignment

a.       Individual responsibilities

b.      Team responsibilities

  1. Debriefing
  2. Check-out
  3. Return to service
  4. Maintaining a personal mission log
  5. Mission critique