46 CFR §109.503

1. (a)Emergency stations signals are established as follows:
   1. (1)The signal to man emergency stations is a rapid succession of short soundings of both the general alarm bell and the whistle, if a whistle is installed, for a period of not less than 10 seconds.
   2. (2)The signal to secure from emergency stations is the sounding of both the general alarm bell and the whistle, if a whistle is installed, three times.
2. (b)The abandon unit stations signals are established as follows:
   1. (1)The signal to man abandon unit stations is a continuous sounding of both the general alarm and the whistle, if a whistle is installed.
   2. (2)If whistle signals are used to direct the handling of lifeboats and davit-launched liferafts, they must be—
      1. (i)One short blast to lower the lifeboats and davit-launched liferafts; and
      2. (ii)Two short blasts to stop lowering the lifeboats and davit-launched liferafts.
   3. (3)The signal to secure from abandon unit stations is the sounding of both the general alarm bell and the whistle, if a whistle is installed, three times.