U.S. Navy: Stealthy Seawolf-Class Sub Hit an Uncharted Seamount

U.S. 7th Fleet has completed a command investigation into the recent collision involving the submarine USS Connecticut in the South China Sea, and it has determined that the sub struck "an uncharted seamount while operating in international waters."

The Connecticut's command will now review "whether follow-on actions - including accountability - are appropriate."

USS Connecticut sustained an underwater collision on October 2 at an undisclosed position in the South China Sea. At least 11 crewmembers sustained minor cuts, scrapes and bruises in the incident, and Connecticut had to surface due to the damage and return to Guam for emergency repairs. 

Military submarines typically operate without active sonar while under way, relying on survey data to navigate safely without giving away their position. That survey data is not always complete enough to reveal underwater obstructions, especially as the seabed is not an entirely static surface. Subs have struck seamounts before: in 2005, the USS San Francisco struck a submerged feature at full speed, resulting in severe damage to her bow. 98 crewmembers were injured, including one individual who later died of his wounds. 

USS Connecticut is a Seawolf-class nuclear powered attack submarine, a class of three hulls that were built and commissioned in the 1990s. Despite their age, the Seawolfs are some of the most advanced submarines ever delivered, and they are reportedly much quieter than the Los Angeles-class and Virginia-class boats that make up the majority of the Navy's attack sub fleet.

With a reported top speed of 35 knots and an outsized magazine of torpedoes and missiles, they are also the fastest and best-armed in the inventory. However, they were also much more expensive to construct than the Los Angeles-class, and the Seawolf program was shortened to three vessels because of post-Cold War cost cuts.