Bridge Navigational Watch Alarm System (BNWAS) requirement

New buildings and existing ships need to be equipped with (BNWAS) in order to monitor bridge activity and detect bridge officers disability which could lead to marine accidents. Although due dates for existing ships are first periodical survey (annual intermediate, renewal) after 1 July 2012 the earliest, it is advisable to arrange retrofitting in forth coaming Dry Docking/SS/ITSS. In this post you will find what BNWAS is and applicable dates depending on vessels type and size.


Application dates



Description of requirement

This Bridge Navigation Watch Alarm System (BNWAS) in simple terms is a timer alarm system that forces watch officers to reset this system in periodic time intervals to insure that they are fully alerted (not sleeping, playing solitaire with bridge computer,etc).

The requirement has the following main technical characteristics:
- After the system has been activated no alarm for a period of 3 to 12 minutes.
-After this period the system initiates a visual alarm on the bridge
- If not reset with a period of 15 seconds an audible alarm on the bridge is activated.
- If not reset with a period of 15 seconds from last audible bridge alarm, a second stage audible alarm is activated in a remote location (ships office, master office).
- If not reset a third stage alarm is activated in a remotely location were other officers can take corrective action within 90 seconds from the initiation of second stage alarm.

In vessels other than passenger vessels the second and the third stage alarms may sound in all of the above location at the same time.

In larger vessels time delay between second and third alarm can be set up to a maximum of 3 minutes.

RESET Function

It should not be possible to initiate the reset function or cancel the audible alarm from a device not physically located in the bridge area providing proper lock out.

The reset function should be a single operation function.

The single operation reset action must be in such a way that will ensure mental alertness of the OOWS.


The dormant periods should not be able to be prolonged by continued activations or any reset devices.

We recommend to contact your radio company and discuss cost and installation requirements.