Wreck of USS San Diego (ACR-6/CA-6)

 military, scuba diving facility / area, First World War 1914-1918, shipwreck, cruiser, United States Navy

Laid down in 1904 as the Pennsylvania Class Armored Cruiser USS California (ACR-6) and commissioned into US Navy service in 1907, the California served with the US Pacific Fleet until 1914 when she was renamed USS San Diego to free up her name for a new Battleship under construction.

As the USS San Diego, she continued to serve with the US Pacific Fleet until 1917 when US involvement in the First World War brought her to the US Atlantic Fleet. Serving primarily as a convoy escort between New York and Halifax, the San Diego was off Fire Island bound for New York City July 19th, 1918 when she was rocked by a tremendous explosion on her Port side at 1105hrs. Immediately taking a list to Port following the blast, the San Diego's crew frantically tried to seal off her rear engine rooms only to find the force of the blast had warped the Cruisers bulkheads and prevented watertight doors from operating. Within minutes both of the San Diego's engine rooms were flooding and being abandoned, robbing the ship of power and causing her list to exceed nine degrees to Port, which allowed water to enter her 6-inch gun ports and further exacerbated the heavy flooding claiming the ship.

Passing the order to abandon ship a mere 12 minutes after the explosion, San Diego's Captain oversaw his crews' evacuation before taking to the lifeboats himself as the Cruiser continued to go down by the bow. Only 28 minutes after the explosion, the San Diego rolled onto her Port side and sank bow-first at this location, taking six crewmen with her to the bottom 110ft below. The sinking of USS San Diego was the only major loss of a US Navy ship during the First World War, and while her Captain believed his ship had been torpedoed by a German Submarine, later investigations pointed to a Submarine-laid mine from the Kaiserliche Marine's U-156 as the likely cause of the San Diego's sinking.

Today, the wreck of the USS San Diego has become a popular SCUBA diving site and lies inverted in 110ft of water, with the top of her hull only 66ft beneath the surface. On the 100th anniversary of her loss, the crew of the USNS Grasp (T-ARS-51) visited the wreck and placed a memorial on the hull to the six lost crew still on duty aboard ship.

www.navsource.org/archives/04/acr6/acr6.htm