If the "dress rehearsal" at sea is anything to go by, the skies will not fall here when the millennium bug strikes at the end of the year. The Irish Marine Emergency Service (IMES) reported no serious incidents yesterday as a Y2K-type glitch affected certain navigational systems at the weekend.
However, the alert still stands for skippers of vessels which have not left port in the last few days. The Week Number Roll-Over (WNRO) was due to affect certain Global Positioning System (GPS) receivers overnight on Saturday.
Mr Gary Delaney, a Cork-based marine consultant and former naval officer, reported a steady flow of phone calls over the weekend to the helpline set up by his company, Charternav GPS.
In only one case was a GPS receiver not working. However, the vessel-owner had not gone to sea.
In Britain, a yacht which left the Scilly isles also requested assistance when it found that its GPS was malfunctioning. However, Dover Coastguard, which covers one of the busiest shipping lanes off the British coast, reported no problems.
The Civil Aviation Authority in Britain also said there had been no problems with aircraft, which only rely on GPS as a secondary system in any case.
A Castletownbere fishing vessel requested assistance some 100 miles south of Cork yesterday, but not for navigational reasons. Its propeller had been fouled by nets.
The St Gervaise, with five crew on board, was taken in tow by the naval patrol ship, LE Aoife, under the command of Lieut Cmdr Pearse O'Donnell. It was able to clear the propeller later and proceed under its own steam.
GPS is a network of 24 satellites developed by the US Air Force to provide navigational information to the military.
Since the system's introduction in the 1970s, it has been adapted for civilian use, most commonly as a precise navigational aid at sea and in the air. It is also used by surveyors, scientists, geographers and engineers on land.
The GPS system calculates time by counting the number of weeks since January 6th, 1980, up to a maximum of 1,024 weeks.
After this, the calendar resets to zero, similar to a car's odometer after 99,999 miles. The next such roll-over is expected in about 20 years.
Vessel-owners were warned that some receivers might not be able to locate the satellites, resulting in a malfunction; they might be affected by a time delay in locating the satellites.
A more serious risk was that the receiver might appear to be working, but might display inaccurate positions, times or dates.
Most experienced vessel-owners do not rely on GPS alone given that most electronic equipment is still categorised as an aid to navigation.
Charternav GPS can be contacted in Cork at (021) 832990.
