The U.S. Coast Guard responded Thursday to a boat on fire roughly three miles off the coast of Carlsbad.
A plume of smoke, visible from the coastline in Carlsbad, was rising from the boat at about 9 a.m.
Coast Guard officials received word that a 50-foot vessel, the Relentless, had left Oceanside Harbor earlier in the morning and was reportedly heading towards Carlsbad.
The Oceanside Harbor Master advised rescuers that the vessel was not a commercial or charter vessel, rather a vessel with a single owner who was likely aboard solo, as the owner used the boat as his residence according to Adam Stanton, a spokesperson for the Coast Guard.
Get San Diego local news, weather forecasts, sports and lifestyle stories to your inbox. Sign up for NBC San Diego newsletters.
The boat owner had not been located and the three Coast Guard cutters that responded to the initial firefight remained in the area continuing to search for any survivors, as of 6 p.m. Thursday evening.
A Coast Guard Jayhawk helicopter crew searched more than 600 square miles, to no avail.
The blaze caused significant damage to the vessel which led to it eventually sinking near a depth of about 1,800 feet, according to a press release from the Coast Guard.
No other information was available.
Please refresh this page for updates on this breaking story. Details may change as more information becomes available.