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Furuno 21x7BB

The View from the Bridge

New Class B AIS Targets Display


AIS clutter may (one day) be more of a problem on small screens than on big ones but that doesn’t mean that the big-ship guys are ignoring the possibility. For the past couple of years now, it’s been an international requirement that all new ships’ radars must include a facility for displaying AIS targets. That’s quite a big step forward from the early years of AIS when the only displays that many ships had were simple, three-line text and numerical data screens, and it’s particularly good for small craft because it elevates AIS to much the same status as radar and ARPA (automatic radar plotting aids).

Just as with the Vesper Watchmate, new-spec, big-ship radars like this Furuno 21x7BB can filter out irrelevant targets to prevent them from cluttering screens. The bad news is that one of the filter criteria that is being used is class. In other words, the new ship radars really can hide Class B AIS targets—and that means us!

But the situation is nowhere near as bad as it sounds because another part of the specification demands that “removing a dangerous target should only be possible temporarily, as long as the operator activates the corresponding control.” So the equipment can hide small craft so long as we are just “clutter,” but if one of us poses a risk of collision, it pops us back on the screen, with a special highlight and an alarm in the bargain.

This article originally appeared in the April 2011 issue of Power & Motoryacht magazine.