In what circumstances must the master of a ship transmit a danger message, as required by SOLAS regulation V/31?

(2) a dangerous derelict; (3) any other direct danger to navigation (e. g. a floating container, ship NUC, unlit fishing vessels, large log, channel swimmers, major yacht race, etc. ); (4) a tropical storm; (5) subfreezing temperatures associated with gale force winds causing severe ice accretion on superstructures; or (6) winds of Beaufort force 10 or more for which no storm warning has been received.