2. a gun or other explosive fired at intervals of about one minute
(tracer bullets can be detected up to six miles, but it is difficult to
pinpoint survivor locations)
3. continuous sounding with any fog signaling apparatus
4. a square flag having above or below it a ball or anything resembling a
ball
5. flames, e.g., from a burning oil barrel (flames are very effective at
night, and have been sighted as far away as 50 miles)
6. red flares, which have been sighted up to 35 miles at night, with an
average of 10 miles at night and about 1 to 2 miles during daylight
7. orange smoke, effective up to 12 miles during the day if winds are
less than 10 knots, with an average 8 mile range
8. slowly and repeatedly raising and lowering arms outstretched to
each side
9. flashes from a signal mirror, with an average detection range of five
miles, but sometimes detectable up to 45 miles
10. dye-stained water, normally green or red, has been sighted up to ten
miles away, with an average detectability of three miles