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

Figure 6-8. Small-Target Recognition Problems
maintain a sense of SRU location within the search area. A
search crew member should be reminded of the importance of
recognizing, reporting, and identifying any object that could
be a survivor or an indication of survivors. While en route
to the search area or during the search, it is helpful to
point out craft or objects that are similar in appearance to
the search object.
3. Lookout positions affect scanning. The best lookout positions
on most aircraft are occupied by the pilot, copilot, and
forward lookouts. If no forward station is available, the
burden of scanning is placed on the pilots. Even with the
aircraft on autopilot, one pilot must concentrate attention
mostly in the cockpit, possibly leaving areas unscanned.
Lookout positions should be as comfortable as possible, and
windows should be clean and free from scratches and oil or
dirt, which may decrease light passing through. Lights inside
the SRU should be kept dim to minimize reflections in the
windows. Vessels and low-flying aircraft tend to pick up salt
on the windshields, and seaplanes pick up salt spray during
takeoff. It may be desirable to open the side windows of
unpressurized aircraft for better visibility. Lookouts should
be posted to maintain a wide field of vision, 360 degrees if
possible, since survivors may not be able to set off their
visual signals until after the SRU has passed.
4. Degradation of scanner effectiveness due to fatigue over the
course of a search is significant. Shifting position on the
SRU every 30 minutes will tend to reduce fatigue from the
effects of the movement of the view across the field of
vision.