When Myojinsho Reef erupted in September 1952, tsunami waves were recorded several times by a. self-registering wave gauge installed on the southwestern coast of Hachijo Island about 130 km from that Reef. The largest one of these tsunamis appeared on 24 September, and it is presumed that this wave ca.used the destruction of the KAIYO-MARU No. 5. Results of investigation of these recorded tsunami waves and other phenomena are reported.