In order to develop Under Water Speaker system (UWS) incorporating species specific audible properties, we examined cetacean sighting survey data collected by hydrofoil crew from four major hydrofoil sea lanes, in 2008 – 2011; “Northern Kyushu (including Busan-Iki-Tsushima routes)”, “Kagoshima”, “Izu-Oshima (including Atami routes)” and “Sado”. In “Northern Kyushu” cetaceans were tended to be frequent in offshore deeper than 100m. In “Kagoshima”, cetaceans including humpback whales were mainly observed in winter. In “Izu Oshima” it was remarkable that sperm whales occurred in winter to early spring with peak of January to March, and also it seemed to be currently increasing. Baird's beaked whales also occurred in winter in addition to regular occurrences in summer. In “Sado”, minke whales were mainly sighted in month from March to June. So as to increase accuracy in cetacean species identification, it is desire to conduct educational lecture and training for cetacean species identification.
