deck jumped overboard to escape the flames and swam to a nearby boat for help while passengers remained trapped. >> can you get back onboard and unlock the boat, unlock the doors so they can get off? >> there's no escape hatch for any of the people onboard. >> reporter: witnesses described hearing explosions during the fire. the charter boat had been outfitted for scuba diving with pressurized tanks as well as propane for cooking onboard. but authorities say it's still too soon to tell how the fire started. the coast guard reporting that so far, they have recovered four bodies while more than two dozen others were still unaccounted for. >> did the crew try to help the other passengers? >> i don't have any additional information regarding that. >> reporter: this morning "the conception's" burned out hull finally sinking shortly after sunrise. only 60 feet off the coast of santa cruz island. >> devastating. tragic. >> reporter: rescuers still searching the shoreline but so far no sign of survivors. >> nbc's gadi schwartz is with us now from santa barbara, california. gadi, what's the latest? >> reporter: yeah, ali, well,