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

quick rescue by marine craft once survivors are located. If
the vessel is radar equipped, it should assist the aircraft in
keeping on course and advise the aircraft when it is 5 miles
from the end of each leg and at the time to turn onto a cross
leg. Advisories of distance off course are based on an
average of several fixes. Whenever the aircraft is within
range, visual bearings should be taken and plotted with radar
ranges. Coordinated patterns should be started before
entering the search area so that full coverage of the area
will be assured. See Figure 5-34. See Appendix E for
procedures for coordinated patterns.
Figure 5-33.
Figure 5-34.
E. 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. If datum is a line instead of a point, the pattern
may be changed to an expanding rectangle. The first leg is usually
directly into the wind or current to minimize navigation errors. A
precise pattern, it requires the full attention of the navigator. If
two aircraft (the maximum that should be used) are assigned to the same