The uses for AIS—Automatic Identification System—continue to evolve far beyond the original intention of collision avoidance for large ships. The first AIS-equipped Personal Locator Beacons have just gone on sale, and it’s only a matter of time before the technology replaces the radar transponder (racon) beacons used on many vital navigation marks.
In fact, in some instances AIS could do away altogether with navigation aids as we know them. Meet the Virtual AIS Beacon, developed to “place” marks where no traditional buoys can exist.
On the rugged coast of New Zealand’s South Island, a barely submerged rock at the mouth of the aptly named Doubtful Sound is an ever-present danger to the many cruise ships that call in there. Within weeks of any buoy being placed there, however, Southern Ocean swells would pluck it away.
The answer was to place an AIS beacon in a solar-powered lighthouse 3½ miles away, transmitting the coordinates of the invisible rock. It shows up on a plotter screen as a marked hazard, just like a fixed nav aid. AIS display manufacturer Vesper Marine, which built the beacon, foresees many other uses for the technology, including marking shifting sandbars or channels, underwater pipelines, even temporary boundaries around race courses, wrecks and so on. Its low-powered 2W transmissions have a range of up to 18 miles. The beacon itself is a small plastic “black box,” needing only an antenna/GPS connection and a power supply.
Don’t expect your familiar channel markers to disappear anytime soon, though. The technology provides a cost-effective and non-intrusive way of marking dangers or areas where it’s not feasible to place or maintain fixed nav aids, and to supplement nav aids in hazardous areas—not supplant them.
Illustration by Colin Hayes