The NYT article says that the 5 crew members were on the deck when the fire broke out. They jumped overboard and went to a nearby vessel and pounded on the hull to raise the alarm, then two of them went back to try and rescue passengers:
Boat ‘Engulfed in Flames’ Leaves Over 30 Missing Off Santa Cruz Island
Boat ‘Engulfed in Flames’ Leaves Over 30 Missing Off Santa Cruz Island