The Medical Examiner’s Office identified the 23-year-old man who died Wednesday morning after snorkeling in Waikiki as Chotaro Watanabe of Japan.

An autopsy will be conducted to determine cause of death.

Police said Watanabe became unresponsive while snorkeling at about 11:10 a.m. Wednesday.

Emergency Medical Services said he was found in ocean waters fronting the Hilton Hawaiian Village, and taken in critical condition to the hospital.

Police said he died at the hospital.

There were no signs of foul play, police said.