Remembering the Loss of USCGC Blackthorn, and Why the Auxiliary Is Important

By Walt Baranger, SO-PB

A few days ago while driving on I-275 across Tampa Bay, Florida, my wife and I stopped at the tollway’s Sunshine Skyway rest area on an islet just off St. Petersburg. I happened to spot a flagpole with a faded Coast Guard ensign, so being a good Auxiliarist I decided to investigate.

I found a black anchor and heavily corroded plaque, including this intriguing inscription:

28 JANUARY 1980 USCGC BLACKTHORN SANK IN TAMPA BAY AFTER COLLIDING WITH MV CAPRICORN

Back home in California that night, research revealed that there is much more to that plaque than a simple collision, and there is even a link to our own Coast Guard station at San Pedro in Sector Los Angeles – Long Beach.

Nearly 45 years ago, the Coast Guard suffered its worst peacetime disaster when the 180-foot World War II-era buoy tender Blackthorn and the 605-foot converted tanker Capricorn collided bow-to-bow at night near the mouth of Tampa Bay.

An additional freak accident involving an anchor immediately made the bad situation far worse.

The initial collision happened quickly; no general alarm or collision warning was sounded aboard Blackthorn. Aside from the bridge crew and a bow watch stander, the Coast Guard crew was largely caught unaware. Capricorn’s crew and harbor pilot were equally taken by surprise moments before the collision.

Even after the collision, a fast initial inspection of the tender revealed no apparently fatal damage. But Capricorn’s anchor had fouled aboard Blackthorn, and as the ships continued to pass the anchor chain ran out to its bitter end and then went taut, opening Blackthorn’s hull to the sea. In addition, Blackthorn was dragged astern and rotated by Capricorn’s momentum.

Within minutes the tanker’s 6½-ton anchor and its taut chain capsized the newly overhauled tender with the loss of 23 Coast Guardsmen.

An alert Capricorn crewman cut the anchor chain loose, or the losses might have been worse.

The capsizing occurred so fast that nothing more was heard from Blackthorn after its initial mayday on Channel 16. A nearby shrimp boat immediately reported the sinking and soon its crew of three rescued more than 20 survivors.

In all, 27 Coast Guard members survived – some after barely escaping from their muster station in the crew mess. Others clung to a wooden quarterdeck shack that floated free from the tender. None of Blackthorn’s lifeboats or inflatable rafts deployed.

Capricorn had no casualties, and suffered relatively minor damage.

In 2000, Seaman Apprentice Billy Flores, USCG, just a year out of boot camp, was posthumously awarded the Coast Guard Medal for saving the lives of his shipmates when he distributed life preservers even as he became fatally trapped inside the sinking tender. At a memorial service in 2020, The Tampa Bay Times reported that Flores’s sacrifice was recalled by at least two survivors in attendance, and that a statue of him was scheduled to be placed in the Circle of Heroes underwater monument off the coast of Clearwater, Florida.

(In another posthumous honor, the Sentinel-class cutter William Flores was commissioned in 2013 and is now based in Miami.)

In the sprawling rescue effort that night, 23 Auxiliarists from Flotilla 11-03, based in Madeira Beach, were cited for operational merit while supporting the Coast Guard rescue both ashore and on scene.

The official reports that followed included findings that basic rules regarding vessel passing, sounding horns and establishing radio contact were not followed. There were many other complicating factors, some as simple as confusing the running lights of other nearby ships, poorly arranged shipping channels, and a lack of crew training following Blackthorn’s recent overhaul.

The Coast Guard report and National Transport Safety Board recommendations are public records, and should be read by anyone interested in marine safety. Many of the factors in the accident will be familiar concerns to recreational boaters as well as seasoned mariners.

The Blackthorn–Capricorn disaster and the Auxiliary’s important role in the rescue was a complete to surprise to me as I parked in the tollway rest area. It was certainly a reminder that training, minding the Rules of the Road and keeping sharp visual and radio watches are always good ways to help avoid accidents.

The Auxiliary’s volunteer public education and operational roles remain important to public safety and the Coast Guard mission. On a winter night 45 years ago, the Auxiliary again answered the call to duty, as it has done since 1939.

So what was the link to San Pedro? It was Blackthorn’s home port during World War II. After the war, Blackthorn permanently moved to stations along the Gulf of Mexico, including 25 years at Mobile, Alabama, where it was heading that balmy January night.