20 bodies recovered after California dive boat disaster
In this photo released by the Ventura County Fire Department, firefighters attempt to extinguish a fire on a boat off the coast of Santa Cruz Island, California Ventura County Fire Department/AFP / HO

Authorities on Tuesday suspended the search for survivors of a scuba diving boat disaster off the California coast after recovering 20 bodies and spotting another four to six trapped in underwater wreckage.

The bodies of 11 women and nine men were transferred to coroner offices following the disaster on Monday, when the 75-foot (23-meter) Conception caught fire and sank with passengers trapped below deck by the roaring blaze.

"Today we will begin the process of mapping DNA profiles of the 20 victims that we have recovered so far, so that they can be compared with family samples," Santa Barbara County Sheriff Bill Brown told a news conference.

The boat had been on a diving excursion around Santa Cruz Island, just west of Santa Barbara in southern California, when disaster struck early Monday.

Five crew members were awake, and jumped into the water when flames burst out around 3:15 am. They were rescued by a nearby pleasure craft.

A total of 39 were on board, officials said.

On Tuesday, emergency officials will attempt to stabilize the boat so that divers can safely enter it and recover remaining victims.

A debris field around half a mile in size will be searched for additional victims and evidence of what caused the fire, said Brown.

The families of 30 of those on board have been contacted, he added.

Seven search missions including three helicopter crews and boats covering around 160 miles up until Tuesday morning failed to spot any signs of survivors, said coast guard captain Monica Rochester.