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

C. Often an SRU, especially aircraft, will not be able to identify
an object on the first pass, thus requiring maneuvering by the SRU. As
it is not unusual for an SRU to lose sight of the target while
maneuvering, it is important for it to have a definite plan for
relocating and identifying sighted objects. SRU commanders should
ensure that each crew member knows that procedure. If something is
sighted, but remains unidentified, these aircraft procedures may prove
useful in relocation:
1. Marking and Relocating Contacts. A smoke marker, illumination
signal, or sea dye marker should be immediately dropped to
mark the approximate location of the sighting. However, smoke
and illumination signals are not used if there is danger of
igniting fuel or oil on the surface. After marking, a
survivor relocation pattern should be executed. Aircraft
should not change altitude if that change may conflict with
other aircraft in the area.
a. A procedure turn can, if properly executed, position
the aircraft back over the sighting area. The procedure turn
recommended is the "90-270" method (Figure 6-17). This method
also works if signals fail to function.
Figure 6-17. Procedure Turn for Investigating Sighting
6-19