On Monday, the US Navy released the report of its investigation of the underwater collision of the Seawolf Class submarine, USS Connecticut, with a seamount in the South China Sea. From the report’s Executive Summary:

On 2 October 2021, Connecticut grounded on an uncharted bathymetric feature while operating submerged in a poorly surveyed area in international waters. This mishap was preventable. It resulted from an accumulation of errors and omissions in navigation planning, watchteam execution, and risk management that fell far below U.S. Navy standards. Prudent decision-making and adherence to required procedures in any of these three areas could have prevented the grounding.

Injuries onboard Connecticut were relatively minor. Eleven total crew members were physically injured.

Connecticut will be unavailable for operations for an extended period of time due to damage sustained during the grounding. The propulsion plant was not affected.

Regarding navigation planning, the report notes: Connecticut’s NAVPLAN for the day of the grounding failed to meet safe navigation standards. The navigation review team, including the CO, failed to identify and properly mark at least ten charted hazards to navigation in the vicinity of the grounding, including two charted water depths shallower than the Commanding
Officer Safe Operating Envelope (COSOE) maximum operating depth.

Failures in watchteam execution related to a temporary course change and discrepancies in charts and plotting data were also noted.

In November, the Connecticut‘s commander, executive officer, and senior enlisted sailor were fired following the results of an investigation into the underwater collision. Connecticut commanding officer Cmdr. Cameron Aljilani, executive officer Lt. Cmdr. Patrick Cashin and Chief of the Boat Cory Rodgers were removed from their positions at the direction of U.S. 7th Fleet commander Vice Adm. Karl Thomas.