---
kind: "section"
citation: "46 C.F.R. § 161.013-7"
title: "46"
number: "161.013-7"
heading: "Signal requirements."
url: "https://uscodex.org/cfr/46/161.013-7"
---

# §161.013-7. Signal requirements.

- (a) An electric light must have a flash characteristic of the International Morse Code for S-O-S and, under design conditions,
  - (1) Each short flash must have a duration of 1/3 second;
  - (2) Each long flash must have a duration of 1 second;
  - (3) The dark period between each short flash must have a duration of 1/3 second;
  - (4) The dark period between each long flash must have a duration of 1/3 second;
  - (5) The dark period between each letter must have a duration of 2 seconds;
  - (6) The dark period between each
- (b) The flash characteristics described in [paragraph (a)](#a) must be produced automatically when the signal is activated.

## Notes

### Source

Source: CGD 76-183a, 44 FR 73054, Dec. 17, 1979, unless otherwise noted.

### Authority

Authority: 46 U.S.C. 3306, 3703, 4302; E.O. 12234, 45 FR 58801, 3 CFR, 1980 Comp., p. 277; DHS Delegation 00170.1, Revision No. 01.4.