1958年敬天丸国際地球観測年航海報告

Keiten-maru left Kagoshima harbour on July 9th, 1958 to complete the multiple ship survey in the western Equatorial Pacific, which was one of the IGY program, in cooperation with Takuyo and Satsuma. The radioactivity was determined on board Takuyo to be terribly high value at the northern side of the expected observing area. All the expected observations were given up with many regrets