Because environmental conditions have a strong impact on boat speed, FISA recognizes world best times instead of world records. A world best time is one recorded on a regatta course that has previously held the World Championships, Olympic Games, or World Cup since 1980. A number of record times were set at the 2005 World Championships held on the Nagara River at Kaizu, Gifu Prefecture, Japan, but due to a fast current caused by heavy rainfall from the remnants of Typhoon Mawar, FISA declared that the race results were not eligible to be considered as world best times.