The crew of the boat destroyed by a fire off California's coast were not aware of any mechanical issues with the vessel, a preliminary report says, APA reports citing BBC.
Initial interviews with the crew revealed no reports of mechanical or electrical issues, the National Transportation Safety Board said.
The NTSB report details events after the boat caught fire on 2 September as passengers slept below deck.
The cause of the blaze that killed 34 people is still to be determined.
Only five people survived, all crew members. The 75-foot-long (23m) scuba-diving boat Conception was anchored metres off Santa Cruz Island, about 90 miles (145km) west of Los Angeles.
Rescue crew recovered the body of the last victim from the water on Monday, police said. Authorities believe all died of smoke inhalation.
"DNA testing is still being conducted to confirm identities of 7 of the 34 victims recovered," Santa Barbara County Sheriff's Office said on Twitter.