The boys -- residents of Carson City, Nev. Stephen Anderson, 16, and Keegan Aiazzi, 17 -- went missing at about 11:30 a.m. on Sat., April 9.
Anderson and Aiazzi were on a scuba diving expedition with a group of 17 other divers, Monterey fire Division Chief Felix Colello said.
Multiple rescue teams were dispatched to search for them, including the Monterey Fire Department and the U.S. Coast Guard, as well as lifeguards and state park rangers.
They searched for nearly 45 minutes, using a Coast Guard helicopter and at least two boats, in addition to another boat from the fire department.
He said searchers finally found the boys on the floor of the bay, about 40 to 60 feet from the surface, near the Intercontinental Hotel on Cannery Row.
Colello said the boys were found still wearing all their diving gear, but were not breathing.
They were taken in an ambulance to a hospital, where they were pronounced dead.
Both Anderson's and Aiazzi's scuba equipment was found on the bay's floor through the efforts of the United States Coast Guard, California State Parks, the Monterey County Sheriff's Office search and rescue dive unit, Monterey Diving Express and Silver Prince Dive Charter Company.
Following a forensic inspection of the gear by master dive repair technician Ernest Bourne, the coroner's office ruled out equipment failure as a cause of death.
Monterey County Sheriff's Office deputies said that the equipment was laboratory tested, as well as being tested in ocean conditions similar to what the boys experienced.
The coroner's office deemed the deaths accidental, due to asphyxia caused by drowning.