Mariners will be aware that there is a risk of computer errors or failures due to the change of century rollover date, known as Year 2000 or Y2K issues. The Commissioners of Irish Lights have made every effort to ensure that all their equipment and systems are Y2K compliant and have sought compliance assurances from their suppliers. Nonetheless, the possibility of failure must be considered and Mariners should exercise caution around the period of the rollover date. Mariners should also be aware that depending on the manufacture, model, and age of their receiver equipment for radio aids to navigation it may not be Y2K compliant. The Commissioners of Irish Lights provide typical aids to navigation as follows: Main Navigation Lights Standby Navigation Lights Emergency Navigation Lights Leading Lights and Sectored Lights Buoy Lights Automated Lightfloats and Lanby Lights Racons on Lighthouses, buoys, ALFs, and Lanbys Radar Target Enhancers on buoys Three differential GPS transmitting stations at Mizen Head, Loophead, and Tory Island Hazard warning sound signals at Lighthouses, Automated Lightfloats, Lanbys, and buoys Many major aids to navigation are monitored remotely via radio or GSM phone links. In the unlikely event of failure of these links, our central monitoring operations will not be immediately aware whether all aids to navigation are functioning correctly. Mariners are requested to inform CIL directly, or via the Coast Radio Service, or by whatever means available if any degradation of the aids to navigation service is observed.