The effect of long stay at coal and iron ore exporting ports in Australia due to port congestion for last three years has remarkably appeared on the bio-fouling and fuel consumption of ships on homeward voyages. The coal export volume from Australia to Japan is so big that a lot of coal carriers destined for Japan are obliged to wait for long time at loading ports in Australia. This effect is a big problem for ship operating companies accompany with the rise of fuel oil price. Bio-fouling also is considered as the causes of transportation of aquatic species. The necessity of counter measures against bio-fouling has been discussed at IMO. Then authors investigated the conditions for last 10 years of port stay of ships for Japan at Newcastle and Gladstone which are main coal export ports. And also the operation record of a coal carrier engaged in Australian service was investigated. The effect of bio-fouling of ship was analyzed based on the coefficient of fuel consumption for unit hour as the evaluation value.
