Figure 6-2.—Distress signals.
A signal sent by radiotelephony consisting of the
spoken word “Mayday”
The international code signal of distress indicated
by NC
A signal consisting of a square flag having above
or below it a ball or anything resembling a ball
Flames on the vessel (as from a burning tar barrel,
oil barrel, and so forth.)
A rocket parachute flare or a hand flare showing a
red light
A smoke signal giving off orange-colored smoke
Slowly and repeatedly raising and lowering arms
outstretched to each side
The radiotelegraph alarm signal
The radiotelephone alarm signal
Signals transmitted by emergency position-
indicating radio beacons
Vessels in distress may use the radiotelegraph
alarm signal or the radiotelephone alarm signal to
secure attention to distress calls and messages. The
radiotelegraph alarm signal, which is designed to
actuate the radiotelegraph auto alarms of vessels so
fitted, consists of a series of 12 dashes sent in 1 minute.
6-13
