The Japanese consulate in Denpasar, the Bali capital, said the group vanished Friday afternoon during a dive trip in the Nusa Penida area on the southeast coast, Kyodo News Service reported.
The group consisted of five visitors from Japan and two Japanese diving instructors based on Bali, consular officials said. All seven were described as experienced scuba divers.
The owner of the Indonesian boat the group chartered for the trip said the seven made two dives without incident in the morning, They went down for a third time and failed to surface.
Nyoman Suarsika, the local police chief, said the weather was bad when the group made the third dive at around 1 p.m.
"The weather was extreme at the time. The wind was strong, with heavy rain," Suarsika said.
A search Friday was suspended for the night and resumed Saturday. No sign of the group had been found Saturday afternoon.
The missing women were identified as Ritsuko Miyata, 59, Emi Yamamoto, 33, Nahomi Tomita, 28, Aya Morizono, 27, Atsumi Yoshinobe, 29, Shoko Takahashi, 29, and Saori Furukawa, 27.