StacksVerified U.S. regulatory reference

46 CFR §161.013-7

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
  1. (a)An electric light must have a flash characteristic of the International Morse Code for S-O-S and, under design conditions,
    1. (1)Each short flash must have a duration of 1/3 second;
    2. (2)Each long flash must have a duration of 1 second;
    3. (3)The dark period between each short flash must have a duration of 1/3 second;
    4. (4)The dark period between each long flash must have a duration of 1/3 second;
    5. (5)The dark period between each letter must have a duration of 2 seconds;
    6. (6)The dark period between each
  2. (b)The flash characteristics described in paragraph (a) must be produced automatically when the signal is activated.