A vessel may supplement the SOUND blast from a WHISTLE with LIGHT SIGNALS as follows:

1 FLASH = Altering course to STARBOUND.

2 FLASHES = Altering course to PORT.

3 FLASHES = Operating astern propulsion.

The duration of each flash should be 1 second, interval between flashes should be 1 second and interval between successive flashes not less than 10 seconds.

This light has to be a all around WHITE light that can be seen for 5 miles minimum!

Hugh Simpson