JP 3-50 National Search and Rescue Manual Vol I - US Navy

a. E-7 corners 23 15N 74 35W to 23 10N 73 25W to 22 20N
73 25W to 22 25N 74 25W to origin.
b. A-6 corners Stony Tavern to Red River bridge to
Gunder Cave to origin.
3. 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. For example:
a. 23 15N 74 35W, 12NM.
b. 23 15N 74 35W, 060 degrees true, 144 X 24 NM.
The Boundary Method or Corner Point Method is preferred
over the Center Point Method because the latter requires more
plotting and makes detection of plotting errors more
difficult. Also, if plotted on a chart of different
projections from the SMC's (e.g., Lambert Conformal vs
Mercator), it results in plots of adjoining areas which do not
have the same boundaries or corner points.
4. Track Line Method. Search areas may be described in this
method by stating the track and the width of coverage. For
example:
NM.
C-2 trackline 24 06N 78 55W to 24 50N 75 46W. Width 50
5. Grid Method. Many areas are divided into grids on local grid
maps. Use of these grids permits accurate positioning and
small area referencing without transmitting lengthy
geographical coordinates. However, all SRUs must have the
same grid charts; SRUs could be endangered if there search
areas overlap due to use of different grid systems. The grid
method is most often used in inland SAR operations. See
Chapter 8 and Volume II Appendix D concerning CAP grids.
6. Georef Method. This method may be used to describe square or
rectangular areas oriented N-S or E-W that coincide with
Georef grids. The Georef method is not normally used. All
SRUs involved in a Georef search should possess Georef grids
to avoid endangering each other.