Submarine Signals

Submarine Emergency Identification Signals

The US Navy has long authorized certain submarine emergency identification signals.  In the past, these signals could be found in Chapter 1 of a current Coast Pilot.  No more.  Notice to Mariners No. 1, the first publication each year of the weekly NTM includes a section called “Special Notice to Mariners Paragraphs” describing, among many other marine safety topics, the Submarine Emergency Identification Signals (I-1.12).

USCG examinations will continue to include questions on these four signals, three of which are described in the Light List/Coast Pilot publication available to license candidates.   While the red, yellow and green signals can be found in the examination excerpts, the white signal must be memorized.  NTM describes the signals as follows:

“U.S. submarines are equipped with signal ejectors which may be used to launch identification signals, including emergency signals. Two general types of signals may be used: smoke floats and flares or stars. A combination signal which contains both smoke and flare of the same color may also be used. The smoke floats, which burn on the surface, produce a dense, colored smoke for a period of fifteen to forty-five seconds. The flares or stars are propelled to a height of three hundred to four hundred feet from which they descend by small parachute. The flares or stars burn for about twenty-five seconds. The color of the smoke or flare/star has the following meaning:

a) GREEN – Used under training exercise conditions only to indicate that a torpedo has been fired or that the firing of a torpedo has been simulated.  [Note that an alternate color had been black which still is an acceptable answer for some questions.]

b) YELLOW – Indicates that submarine is about to come to periscope depth from below periscope depth. Surface craft terminate antisubmarine counter-attack and clear vicinity of submarine. Do not stop propellers.

c) RED – Indicates an emergency condition within the submarine and that it will surface immediately, if possible. Surface ships clear the area and stand by to give assistance after the submarine has surfaced. In case of repeated red signals, or if the submarine fails to surface within reasonable time, she may be assumed to be disabled. Buoy the location, look for a submarine buoy and attempt to establish sonar communications. Advise U.S. Naval authorities immediately.

d) WHITE – Two whiteflares/smoke in succession indicates that the submarine is about to surface, usually from periscope depth (non-emergency surfacing procedure). Surface craft should clear the vicinity of the submarine.”

These emergency identification signals should not be mistaken for the light assigned by the International and Inland Rules of the Road to submarines (intermittent yellow (amber) flashing beacon).

A green signal, floating in the air from a parachute, about 300 feet above the water, indicates that a submarine _________.
A. has fired a torpedo during a drill.
B. will be coming to the surface.
C. is on the bottom in distress.
D. is in distress and will try to surface.
Answer: A
A yellow signal floating in the air from a small parachute, about 300 feet above the water, would indicate that a submarine ______________.
A. has fired a torpedo during a drill
B. is about to rise to periscope depth
C. is on the bottom in distress
D. is disabled and unable to surface
Answer: B
The color of the signal flare sent up by a submarine about to surface because of an emergency on board is ____________.
A. white
B. green
C. yellow
D. red
Answer: D
During a training exercise a submarine indicating that a torpedo has been fired will send up smoke from a float. The smoke's color will be __________.
A. black
B. red
C. orange
D. yellow
Answer: A [Note that black no longer is listed as an alternative to green in the latest NTM.]
The color of the signal flares sent up by a submarine about to surface from periscope depth is __________.
A. green
B. yellow
C. white
D. red
Answer: C