New York Codes, Rules and Regulations
Title 21 - Miscellaneous
Chapter XXIV - The Port Authority Of New York And New Jersey
Subchapter C - Marine Terminals
Part 1242 - Dockage
Dockage Rules
Section 1242.31 - Fire signal

In the event of fire occurring on board any watercraft in a terminal, except watercraft under way, such watercraft will sound five prolonged blasts of the whistle or siren as an alarm indicating fire on board or at the dock to which the watercraft is moored. Such signal may be repeated at intervals to attract attention, and is not a substitute for, but may be used in addition to other means for reporting a fire. The words "prolonged blast", as used in this section, shall mean a blast of from four to six seconds duration. The signal is not to be used for other purposes.