A BNWAS must be fitted in compliance with SOLAS reg. V/19 as follows:
(1) cargo ships of 150 GT and upwards and passenger ships irrespective of size constructed on or after 1 July 2011; (2) passenger ships irrespective of size constructed before 1 July 2011, not later than the first survey after 1 July 2012; (3) cargo ships of 3, 000 GT and upwards constructed before 1 July 2011, not later than the first survey after 1 July 2012; (4) cargo ships of 500 GT and upwards but less than 3, 000 GT constructed before 1 July 2011, not later than the first survey after 1 July 2013; and (5) cargo ships of 150 GT and upwards but less than 500 GT constructed before 1 July 2011, not later than the first survey after 1 July 2014. The bridge navigational watch alarm system shall be in operation whenever the ship is underway at sea.