Precise bathymetric soundings were made in two crater lakes (Shinmiyo and Tairo-ike) in Miyake Island. These lakes were investigated by Yoshimura in 1932 (Yoshimura et al. 1936), but accurate soundings have not been made. The present soundings were made as a part of basic researches on the water balance and water supply of the lakes which are main fresh water resources of the island. Depth-area-volume relations are shown in Tables 1 and 2.
