1. Search Patterns W S
CG Addendum (Chap 3, Appendix H Section H.7 )

2. Instructor notes
This lesson plan is designed to help the students understand Search Patterns.
The students will be given a scenario for each pattern type.
They will be required to develop the pattern based on the scenario and answer the associated questions.

3. Objectives DEMONSTRATE search pattern nomenclature
APPLY standard search pattern designations
IDENTIFY the purpose of each search pattern
FORWARD a search pattern to an SRU
SELECT the appropriate search pattern
PLOT a search pattern
4.1.1 DEMONSTRATE the understanding of Commence Search Point (CSP), Search Leg, Cross Leg, Creep, Major Axis, and Minor Axis with 80 percent accuracy.
REFERENCE: U.S. Coast Guard Addendum, Section H.7.2.
4.1.2 APPLY the standard search pattern designations used to describe search patterns with 80 percent accuracy.
REFERENCE: U.S. Coast Guard Addendum, Section H.7.3 and Table H-44.
4.1.3 IDENTIFY the purpose of each search pattern: Track Line, Expanding Square, Sector, Creeping Line, and Parallel with 80 percent accuracy.
REFERENCE: U.S. Coast Guard Addendum), Section H.7.3.
4.1.4 FORWARD a search pattern to a Search and Rescue Resource Unit (SRU) utilizing the Corner Point Method or Center Point Method with 80 percent accuracy.
REFERENCE: U.S. Coast Guard Addendum, Section H
4.1.5 SELECT the appropriate search pattern to use for given circumstances without error.
REFERENCE: U.S. Coast Guard Addendum, Section H.7.3.

4. Search Area Designation
How are search areas designated?
A, B, C...
When does it become a B search?
H Search Area Designation (naming). Search areas shall be designated using a letter (A, B, C…) sequentially for the overall search area. A new letter shall be assigned each time the search planner establishes a datum or drifts a datum. In the course of a search if a new independent datum is established due to new information or other circumstances, that datum shall continue with the next search letter designation for that case. Sub-areas to be searched by specific search units (or combination of units) shall be numbered sequentially and associated with the overall search area by preceding the number with the letter designation of the overall search (A-1, A-2, etc.).
When drift is re-calculated.
CSP
CSP
A-1
A-2

5. Describing Search Areas
The standard methods used to designate
search areas
Corner Point Method
Center Point Method
H Describing Search Areas. SRUs must be able to plot the search area on the basis of information received from the SMC. Several standard methods are used to describe search areas:
(a) Boundary Method. Any square or rectangular area oriented east/west or north/south can be described by stating the two latitudes and two longitudes. Any inland search area that is bounded by prominent geographical features can be described by stating the boundaries in sequence.
(b) Corner Point Method. This can be used for any area (except circular areas) that can be described by stating the latitude and longitude, or geographical features, of each corner, in sequence.
(c) Center Point Method. Convenient for describing all but irregular search areas and quickly transmitted, this method gives latitude and longitude of the center point and the search radius, if circular, or the direction of the major axis and applicable dimensions, if rectangular.
(3) Center Point-Landmark. The center point, or datum, may be designated by a bearing and distance from a geographic landmark.
The Boundary Method or Corner Point Method is preferred over the Center Point Method.
SAROPs will give the center point, major axis, minor axis, length and width and all four corner points.
(d) Track Line Method. Search areas may be described in this method by stating the track and the width of coverage.

6. Describing Search Areas
BLDG
ABAND LT HOU
Point Comfort
SMC will pass this information from the SAROPS summary.
20 NM
44-30 N
62-20 W
Corner Point Method. Described by stating the latitude and longitude, or geographical features, of each corner, in sequence.
Center Point Method, this method gives latitude and longitude of the center point and the search radius, if circular, or the direction of the major axis and applicable dimensions, if rectangular.
* Positives:
Very common, people are used to it Quick and not that many numbers to pass over the radio.
* Negatives:
High possibility for error, if you miss plot the
Lat/Long, you would end up searching in the
wrong area and never realize it.
Corner Point Method Positives: Most search areas are rectangle or squares, if you miss plot one position you have a good visual reference. Negatives: It’s a lot of numbers being passed over the radio, hopefully you can get them the SAP before they launch.
Center Point or Corner Points will be passed to the SRU
12 NM
060 T

7. Search Pattern Selection

8. What is your datum accuracy? search area size? SRU’s? environment?
Time, current
search area size?
Large or Small
SRU’s?
Number, type, speed
environment?
FAC or Hurricane
Search target
Large or small
H.7.1 Factors in Selection
Search pattern selection depends on many factors, including
accuracy of datum,
search area size,
number and capabilities of SRUs,
environmental conditions,
size of search target, and
type of survivor detection aids and SRU sensors.
While the factors are interrelated, some may be more important than others. The SMC should satisfy the more important factors while meeting others as nearly as possible.
detection aids?
Visual, Radar, NVG?

9. Nomenclature 3nm Major Axis Minor Axis Cross Legs Commence Search Legs
Sweep Width
Commence
Search Point
(CSP)
Search Legs
Track space
Major Axis
H Commence Search Point (CSP) is the location in the search pattern where the SRU begins searching. Specifying the CSP allows the SRU to efficiently plan the en route track, and ensures that SRUS are separated and that the SRU begins search at the desired point and time.
H Commence Search Point Guidance. All factors, including environmental conditions and available resources, should be carefully considered when determining where to place the commence search point (CSP) for particular search areas.
(a) Creeping Line Single-Unit (CS). The CSP is located 1/2 track spacing inside the corner of the search area. Same for Parallel search patterns.
H Search Leg is the long leg along the track of any pattern.
H Crossleg is the connection between two search legs.
Track spacing (S) is the distance between adjacent parallel search legs. The desired track spacing is a function of corrected sweep width, which is a measure of detection capability and will vary with search object type and environmental conditions, and the desired coverage. For a given desired coverage, the more difficult an object is to detect, the closer together the search legs must be.
Sweep Width is a measure of detection capability based on search object and sensor characteristics, weather, and other factors.
3nm
Minor Axis

10. Nomenclature Creep N Direction of Creep W E S CSP
Creep is the general direction in which an SRU moves through a rectangular or square area, normally the same direction as the crosslegs.
CSP S

11. Search Pattern DesignationCS BS
TSN SS
TSR
Shoreline
Search Pattern Designation
A coded system of letters is used to designate search patterns. PS VS

12. Search Pattern Designation
First letter designates the Pattern Type
P Parallel track V Sector
C Creeping line B Barrier
S Square T Trackline
CG Addendum Table H-44 Search Pattern Summary has the complete search pattern list and summary of each.
The first letter designates the major pattern characteristic.
* These are the most common Search Patterns used in the U. S. Coast Guard today.
* There are more Search Patterns discussed in the CG ADDENDUM but these are what you will use most of the time.
* When a Search Pattern has been designated, the first letter lets the SRU know what type of pattern it is. P

13. Search Pattern Designation
Second letter designates number of units
S Single unit M Multi-unit
The 2nd letter designates whether you have one or more than one SRU conducting the same Search Pattern.
The second letter denotes SRU number ("S" is a single-unit search; "M" is a multiunit search). P S

14. Search Pattern Designation
The third letter designates specialized SRU patterns or instructions.
N Non return R Return T S R
* The third letter designates specialized SRU patterns or instructions.
The two most often used are Return & Non-return
There are others in the addendum but are not typically used.

15. Trackline Patterns Criteria
Used when the intended route of the search object is known.
A rapid and reasonably thorough coverage of the missing craft's proposed track.
H Trackline Patterns (T) are used when the intended route of the search object is known. A route search is usually the first search action since it is assumed that the target is near track, and that either it will be easily seen or the survivors will signal. The trackline pattern is a rapid and reasonably thorough coverage of the missing craft's proposed track and area immediately adjacent, such as along a datum line.

16. Trackline Patterns Trackline Single-unit Non-return (TSN) A B CSP
(a) Trackline Single-Unit Non-Return (TSN) search is made along the track or datum line. The letter "N" in the third position indicates that the pattern makes one or more searches along the track, but the search terminates at the opposite end of track from where it began. B

17. Trackline Patterns
Trackline Single-unit Return (TSR)
CSP A
(b) Trackline Single-Unit Return (TSR) has the CSP offset ½-search track spacing from the trackline or datum. The SRU runs up one side and down the other, ending one-track space from where it began.
CSP offset ½-search track spacing from the trackline B

18. Parallel Patterns Used to cover large search areas.
Criteria
Used to cover large search areas.
Provides uniform coverage.
Only an approximate initial position is known.
H Parallel Patterns (P) are best adapted to rectangular or square areas and have straight search legs that are usually aligned parallel to the major axis. Parallel patterns are normally used for large, fairly level search areas, where only approximate initial position is known, and when uniform cover-age is desired.

19. Parallel Track Single Unit (PS)
Major Axis
(a) Parallel Track Single-Unit (PS) is used by single SRUs for searching rectangular areas and is mostly used by fixed-wing aircraft. Search legs are oriented along the major axis, providing longer legs and fewer turns.
CSP is located a ½ track spacing in from the corner similar to the CS. This is not stated in the Addendum.
CSP
Minor Axis

20. Creeping Line Patterns
Criteria
Used to cover one end of an area first or
To change direction of the search legs.
CSP is located 1/2 track spacing inside
the corner of the search area.
H Creeping Line Patterns (C) are a specialized type of parallel pattern where the direction of creep is along the major axis, unlike the usual parallel (P) pattern. They are used to cover one end of an area first, or to change direction of the search legs where sun glare or swell direction makes this necessary.
Creeping Line Single-Unit (CS). The CSP is located 1/2 track spacing inside the corner of the search area.
NOTE: SAROPs will give a CS search pattern on a normal basis. Explain to students why.

21. Creeping Line Single Unit (CS)
Search Legs are oriented to the minor axis
Major Axis
CSP

22. Square Patterns Criteria Used to search a small area.
Some doubt exists about the distress position
Provides uniform coverage.
H Square Patterns (S) are used to search a small area when some doubt exists about the distress position. They provide more uniform coverage than a sector search and may be expanded. Square searches are referred to as expanding square searches beginning at datum and expanding outward.

23. Square Patterns Execution CSP is at datum.
First leg is in the direction of drift.
All turns are 90 degrees to the right.
Search leg length is increased by
one track space on every other leg.
( a) Square Single Unit -- Sierra Sierra (SS).
(1) The first leg is normally in the direction of the search object's drift. All course changes are 90 degrees to the right.

24. Square Single Unit (SS)3
S = 1 NM 1 4 3 1 2 4 2 4

25. Sector Patterns Criteria Datum is established within close limits.
High coverage is desired in the immediate vicinity of datum.
Area to be searched is not extensive.
H Sector Patterns (V) These patterns may be used when datum is established within close limits, a very high coverage is desired in the immediate vicinity of datum, and the area to be searched is not extensive. The patterns resemble the spokes of a wheel and cover circular search areas. Datum is located at the center of the wheel and should be marked with a suitable floating marker. By marking datum, the SRU has a navigation check each time the SRU passes through the center of the search area. While there are many types of sector search patterns, a six sector pattern is usually used. It consists of three equilateral triangles with one corner of each triangle at datum. See Figures H-48 and H-49. The search radius is also the length of every leg.

26. Sector Patterns Execution CSP is at datum.
First leg is in the direction of the object’s drift.
All turns are 120 degrees to the right.
Second search begins 30 degrees to the right.
Sector Search Patterns
(1) Sector Search Pattern: Single Unit -- Victor Sierra (VS), Figure H-48. When practical, the first leg of the search is normally in the direction of search object drift. All turns in this pattern are 120° to the right. All legs of the search pattern are equal to the chosen radius. Upon completion of the pattern, a second pattern is started with the heading of the new first leg 30° to the right of the final course of the first pattern.

27. Sector Single Unit (VS)
*What is the radius?
You must determine corrected sweep width first, then double it for surface craft.
Have them open their addendum to page Read chapter
Discuss the initial response is 1.0 coverage factor.
Aircraft fly at level flight for 1 minute at search speed, offset 6 times. Discuss if this is realistic?
Surface is twice the corrected sweep width.
Now turn the page and it has a table for initial track spacing, totally different than corrected sweep width.
This is what the small boat community has been trained to do.
Just make sure they tab this section and read it, there are different ways to do it.
CSP
Corrected Sweep Width (W) is equal to the 2x radius and determined by the search object.

28. Sector Single Unit (VS)
Second Pattern
First pattern
Second pattern off set 30 degrees to the right

29. Cross-Over Barrier Pattern
High current areas
Containment of Datum is paramount
Search legs perpendicular to movement of target
H.7.3.9
Drift Compensation During a Search. If the target and SRU are in motion, it may be necessary to consider the relative motion plot of the SRU with respect to the target, especially in high current areas. Failure to account for target motion may cause the target to drift out of the search area before the search is completed. Even if the target remains in the search area, the pattern relative to the target may be so distorted that POD is greatly reduced.
(2) Cross-Over Barrier Pattern (B). These patterns have search legs perpendicular to the expected relative movement of targets.

30. Cross-Over Barrier Pattern (BS)
Distress
Position
Here’s an example of a person falling off of a bridge and drifts in the direction of current with containment by land on either side.
SRU runs back and forth along the down current end of the search area.
Current

31. Shoreline Search Small vessels or aircraft: low altitudes & speeds
close inspections of the terrain
Consider the possibility of survivors clinging to navigational aids such as buoys, or to rocks offshore
IAMSAR Manual Volume 2
Shoreline Search
The marine equivalent to the contour search is the shoreline search. Small vessels, or aircraft capable of safely flying at low altitudes and speeds, are normally used in order to pass close enough to the shoreline to permit careful inspection. Vessels engaged in shoreline searches must be aware of navigational constraints and any limitations imposed by sea conditions. Search planners should consider the possibility of survivors clinging to navigational aids such as buoys, or to rocks offshore. Survivors may make their way to any dry land they may drift close enough to see. Survivors may also anchor their boat or raft or tie it to an offshore navigational aid if they drift into shallow water but still cannot see land or believe they cannot make it to shore unaided. Search facilities should pay special attention to any such possible places in their sub-areas where the survivors may have succeeded in arresting their drift.

32. Example: SMC’s intention is to search .5 NM offshore
Shoreline Search
Example: SMC’s intention is to search .5 NM offshore

33. Review What axis do the search legs of a PS run along?
Where is CSP for a VS? a PS?
What direction does the 2nd search start in a VS?
Parallel Patterns (P) are best adapted to rectangular or square areas and have straight search legs that are usually aligned parallel to the major axis.
VS = Datum or the center, When practical, the first leg of the search is normally in the direction of search object drift.
PS = The CSP is located 1/2 track spacing inside the corner of the search area.
Upon completion of the pattern, a second pattern is started with the heading of the new first leg 30° to the right of the final course of the first pattern.

34. Review What direction are all turns in an SS?
Which pattern is used for large area, uniform coverage and the approximate position is known?
Square searches are referred to as expanding square searches beginning at datum and expanding outward. The first leg is normally in the direction of the search object's drift. All course changes are 90 degrees to the right.
PS - Parallel patterns are normally used for large, fairly level search areas, where only approximate initial position is known, and when uniform cover-age is desired.
All turns in this pattern are 120° to the right. All legs of the search pattern are equal to the chosen radius.
What is the direction of all turns in a VS?

35. Plotting Search Patterns
Each ppt screen plays out and demonstrates one way to plot a pattern.
Some things to advise the students are:
SAROPS counts each leg as “legs” many times SRU’s will count only the search legs.
SAROPS plots some patterns differently than the addendum. Specifically the SS and the TSR.

36. Plotting a “PS” Determine Search Area Major Axis Minor Axis1 2 3 4

37. Measure ½ track spacing in from the corners
Plotting a “PS”
Measure ½ track spacing in from the corners
Major Axis
Minor Axis 1 2 3 4

38. Connect the marks to make the patterns size
Plotting a “PS”
Connect the marks to make the patterns size
Major Axis
Minor Axis 1 2 3 4

39. Mark CSP, then mark full track spacing
Plotting a “PS”
Mark CSP, then mark full track spacing
Major Axis
Minor Axis
CSP 1 2 3 4

40. Lay out search legs and erase every other cross leg
Plotting a “PS”
Lay out search legs and erase every other cross leg
Major Axis
Minor Axis
CSP 1 2 3 4

41. Label a minimum of three legs
Plotting a “PS”
Label a minimum of three legs
Major Axis
CSP
C- ºT/ ºC
D NM
D NM
C- ºT ºC
C- ºT/ ºC
D NM S KN 1 2 3 4

42. Plotting a “CS” Determine Search Area Major Axis Minor Axis1 2 3 4

43. Measure ½ track spacing in from the corners
Plotting a “CS”
Measure ½ track spacing in from the corners
Major Axis
Search Area
Minor Axis 1 2 3 4

44. Connect the marks to make the pattern size
Plotting a “CS”
Connect the marks to make the pattern size
Major Axis
Minor Axis 1 2 3 4

45. Mark CSP and measure a full track spacing
Plotting a “CS”
Mark CSP and measure a full track spacing
Major Axis
Minor Axis
CSP 1 2 3 4

46. Lay out search legs and erase every other cross leg
Plotting a “CS”
Lay out search legs and erase every other cross leg
Major Axis
Minor Axis
CSP 1 2 3 4

47. Label a minimum of three legs
Plotting a “CS”
Label a minimum of three legs
C- ºT ºC
D NM
D NM S KN
C- ºT/ ºC
C- ºT/ ºC
D NM
CSP 1 2 3 4

48. Plot datum and arc a full track spacing around it
Plotting a “VS”
Plot datum and arc a full track spacing around it 1 2 3 4

49. Lay down the first track line in the direction of drift
Plotting a “VS”
Lay down the first track line in the direction of drift 1 2 3 4
Datum
(CSP)

50. Mark track spacing on either side of the line
Plotting a “VS”
Mark track spacing on either side of the line 1 2 3 4
CSP

51. Lay out the remaining track lines by connecting the marks
Plotting a “VS”
Lay out the remaining track lines by connecting the marks 1 2 3 4
CSP

52. Plotting a “VS” Label three legs minimum CSP C- ºT/ ºC D- NM1 2 3 4
CSP
D NM S- KN
C- ºT/ ºC
C- ºT/ ºC
D NM

53. Plot datum and mark a full track spacing around it
Plotting a “SS”
Plot datum and mark a full track spacing around it 1 2 3 4

54. Lay down first search leg in the direction of drift
Plotting a “SS”
Lay down first search leg in the direction of drift 1 2 3 4
CSP

55. All turns are 90° to the right.
Plotting a “SS”
All turns are 90° to the right. 1 2 3 4
CSP

56. Add one track spacing every other search leg
Plotting a “SS”
Add one track spacing every other search leg 1 2 3 4
CSP

57. Plotting a “SS”
Repeat for number of legs required 1 2 3 4
CSP

58. Plotting a “SS” Label all legs CSP C- ºT/ ºC D- NM 1 ½ 2 3 4 C- ºT/ ºC2 3 4
C- ºT/ ºC
D NM
C- ºT/ ºC
D NM
C- ºT/ ºC
D NM
C- ºT/ ºC
D NM
CSP
C- ºT/ ºC
D NM
C- ºT/ ºC
D NM
NOTE TO INSTRUCTOR
SAROPS plots this a bit different than the addendum
The addendum does not explain how big the expanding square is to be. So confusion is created especially with how long the last leg should be.
SAROPS provides a radius on how big the expanding square is to be.
The legs on an expanding square for SAROPS purposes (and the plotting the students will do since they are getting SAROPS search pattern summary’s) will end ½ track space in from the sides of the box that the radius makes.
C- ºT/ ºC
D NM

59. Using the target's intended track line, plot positions along the track
Plotting a “TSR”
Using the target's intended track line, plot positions along the track 1 2 3 4

60. Using 1/2 track spacing, arc a circle around each plotted position
Plotting a “TSR”
Using 1/2 track spacing, arc a circle around each plotted position 1 2 3 4

61. CSP will be located at one end
Plotting a “TSR”
CSP will be located at one end 1 2 3 4
SAROPS and the addendum differ
SAROPS and what the students get have the TSR going around the destination point. CGADD has the cross legs for the TSR going over the destination point.
CSP

62. Plotting a “TSR” Label all legs CSP C- ºT/ ºC C- ºT/ ºC D- NM D- NM1 2 3 4
CSP
C- ºT/ ºC
D NM
C- ºT/ ºC
D NM
C- ºT ºC
D NM
C- ºT/ ºC
D NM
C- ºT/ ºC
D NM S KN

63. Questions? ? ? ? ? ? ? ? ? ? ? ? ? ?