Boat operators are facing a potential technological hazard which could pose danger on the seas.

Known as the Global Positioning System Rollover, the problem is similar to the feared Millennium Bug and may affect anyone on the water with a GPS on their vessel.

Bermuda Harbour Radio have put out a warning to all users in order to avoid any disasters at sea during in the summer.

Harbour Radio spokesman Scott Simmons said the dangers are somewhat unknown, similar to the Y2K problem, and it is difficult to estimate what, if any, effect there will be.

"It could be the inconvenience of being out at sea and not knowing exactly where you are,'' he said. "Or with respect to hazards such as reefs, the possible consequences could be anything from misjudging your approach to channels or running aground or being completely lost.'' The situation has arisen as GPS relies upon a weekly numbering system, which started on January 5, 1980. On August 22 the data message -- which can only provide for numbers up to 1,024 -- will have reached 1,023 weeks, when it will then rollover back to 0.

Many GPS receivers, unless repaired, will not account for this change and may work as though the date is January 6, 1980.

The result could be nothing or a complete lock-up of the equipment or the supplying of erroneous information -- which could lead to vessels being unable to pinpoint their exact location.

And Mr. Simmons said users -- of whom there could be hundreds in Bermuda -- would need to ensure their gear was checked and tested in order to avoid potential pitfalls. "It will be the responsibility of the user to account for this changeover themselves, the satellites will simply start broadcasting the new week number.

"How it will affect your GPS unit will depend on the brand and model. Some may display inaccurate date information, others may calculate incorrect navigation data or stop providing positions altogether.

"If this rollover was not taken into account at the time your GPS was designed and built, then you may have problems.'' He added that owners should consult with the manufacturer of their equipment.

In addition, a US Coastguard website also offer advice. It can be found at www.navcenuscp.mil/gps/.

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