A 28-foot sailboat sinks off Balboa Peninsula on Wednesday evening.

A 28-foot sailboat sinks off Balboa Peninsula on Wednesday evening. (Courtesy John Schiesser / June 21, 2012)

A passenger on a 28-foot sailboat escaped unscathed after the boat beached in shallow water and sank off Balboa Peninsula, authorities said Thursday.

The boat was discovered rocking in the surfline off F Street about 7:50 p.m. Wednesday, according to the Newport Beach Fire Department.

The sailboat's skipper was on shore at the time, according to the Fire Department.

Orange County Sheriff's Department Harbor Patrol deputies and Newport Beach lifeguards tried to pull the boat out of the inshore trench where it was stuck, fire authorities said.

Attempts to navigate it out of the trench failed, and the boat took on water and sank, leaving only the mast above the water.

The sailboat broke apart and was unsalvageable as of Thursday morning, fire authorities said. The city's Municipal Operations Department, along with Newport Beach firefighters, are expected to lead the debris cleanup effort.

— Lauren Williams

Twitter: @lawilliams30