Class-B AIS For Smaller Vessels

All ocean-going ships over 300 gross tons are required under the international Safety of Life at Sea (SOLAS) to carry an approved Class-A AIS transponder as an aid to collision avoidance and to facilitate vessel traffic monitoring by shore-based control centers. With the advent of the Class-B AIS standard, recently adopted by the International Maritime Organization, smaller vessels not subject to the SOLAS carriage requirements can also take advantage of the benefits provided by AIS technology."

The R4B transponder transmits its GPS position coordinates, course and speed over ground, vessel name, call sign, type and size through a VHF data channel to all AIS-equipped vessels in the area. The R4B also receives data from all Class-A or -B transponders in the vicinity for display on an electronic chart system or plotter. In addition, vessels fitted with the R4B can be monitored by base stations ashore, providing a useful tool for fleet tracking and managing commercial fleets in coastal waters, harbors and inland waterways. The AIS transponder will also facilitate search-and-rescue operations.

The R4B can improve situational awareness for operators of smaller commercial and recreational craft, by providing an automatic data exchange between AIS-equipped vessels, giving each of them a clear picture of the other vessels' position and movements.

The compact R4B transponder contains a built-in GPS, which provides position coordinates, as well as course and speed over ground, for the AIS broadcasts. The unit has a standard NMEA interface for output to electronic chart systems and plotters, as well as an external alarm key.