Captain Robert Thomas Yoho Jr. failed to ensure that all passengers were on board his Atlantis Reef Divers vessel before leaving a dive site off Fort DeRussy beach, said Capt. Frank Whipple, commander of the Coast Guard Marine Safety Office.

Yoho, who has held an ocean operator's license since 1983, is to appear before an administrative judge Jan. 13. The judge can suspend or revoke his license, place him on probation or dismiss the case. Whipple stressed the negligence charge is not a criminal or civil action.

"He's required by the regulations to account for people when they get on the boat and when they leave the boat," Whipple said. "He went out with X number of people; he came back with X minus one. I don't need much evidence to show that."

Akemi Hoshino, 24, of Saitama, Japan, drowned after participating in an introductory scuba dive session about 200 yards off shore.

Police said she was dropped off in the ocean about 9:40 a.m. and was discovered missing after the boat returned to the pier about an hour later. A diver from another commercial company pulled Hoshino's body to the surface.

Atlantis spokesman Terry O'Halloran has said the two instructors assigned to the eight novice divers accounted for all the divers before heading back in.

Neither O'Halloran or Whipple would comment on the continuing Coast Guard investigation.

Whipple said the investigation could take months to complete. The Coast Guard is waiting to interview witnesses, some of whom have returned to Japan, and for a determination from the coroner's office, Whipple said.

Meanwhile, Atlantis Reef Divers has suspended its scuba diving operation indefinitely, O'Halloran said.

Whipple said the Hawaii Coast Guard initiated 25 negligence, misconduct or law violation cases last year.

"(But) this is a high profile case," he said. "It affects the economic climate in Hawaii."

But Hawaii Visitors Bureau spokesman David McNeil claimed that the deaths of Hoshino and the drowning of 54-year-old Tomoko Yanase while on an Atlantis Reef Divers expedition off Waikiki last April were isolated incidents.

"We don't anticipate it to affect visitor numbers," O'Neil said. "The circumstances surrounding (the) tragic incident remain unclear. However, it does provide the impetus to review the safety procedures of the dive industry."

O'Halloran said the company is focusing on "prevention" and will concentrate on "examining how water recreation safety can be improved."

Whipple said the Marine Safety Office employs a staff of 60 whose job is to "prevent casualties."

O'Halloran said his company is cooperating fully with the Coast Guard.

"Any information we get, they have," he said. "We want answers too."