The USCGC Blackthorn (WLB-391) was a 180-foot seagoing buoy tender for the US Coast Guard. A buoy tender is a type of vessel used to maintain and replace navigational buoys. Prior to navigational buoys, ships might run into rocks, small almost submerged islands, or coral reefs. It would be nice if every underwater danger could have a lighthouse, but that just isn’t feasible. Buoys, on the other hand, and markers serve to direct the operator of the water vessels on the safe course to take. They warn the operator of the underlying dangers in the waterways. Navigation buoys and markers are also effective navigation aid in directing the water vessel operator on the best route to use. They aid in determining the safest way through the waters.
The Blackthorn was one of 39 original 180-foot seagoing buoy tenders built between 1942-1944. All but one of the original tenders, USCGC Ironwood (WLB-297), were built in Duluth, Minnesota, which makes me wonder if my Uncle Bill Spencer, or his sisters, Laura Fredrick and Ruth Wolfe might have worked on it. Blackthorn’s preliminary design was completed by the United States Lighthouse Service and the final design was produced by Marine Iron and Shipbuilding Corporation in Duluth. On May 21, 1943, the keel was laid, the vessel was launched on July 20, 1943, and commissioned on March 27, 1944. The original cost for the hull and machinery was $876,403.
The Blackthorn was initially assigned to the Great Lakes for ice-breaking duties, but was resigned to San Pedro, California after just a few months. For several years the vessel served in San Pedro and then it was moved to the gulf coast region to serve in Mobile, Alabama. From there it was transferred to Galveston, Texas for the final years of its service until it was involved in an accident.
In 1979-1980, Blackthorn underwent a major overhaul in Tampa, Florida. The work was finished and on January 28, 1980, while leaving Tampa Bay after the completion of the overhaul, she collided with the tanker SS Capricorn near the Tampa Bay Sunshine Skyway Bridge. The Blackthorn capsized resulting in the deaths of 23 crew members. The cutter was raised for the investigation, but ultimately, instead of fixing it, Blackthorn was scuttled in the Gulf of Mexico after the investigation was complete. She is currently serving as an artificial reef for recreational diving and fishing.