The Admiral's Cup was an international yachting regatta. For many years it was known as the unofficial world championship of offshore racing. The Admiral's Cup regatta was started in 1957 and was normally a biennial event (occurring in odd-numbered years) which was competed for between national teams. However the event was not staged in 2001 and was last held in 2003. It was cancelled at short notice in 2005. The 2003 event did not follow the normal format and allowed entries from any yacht club affiliated to a national authority, thus allowing the possibility of several teams per country.