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Commander Submarine Squadron 12
The official website of Commander, Submarine Squadron Twelve (CSS 12)

Mailing Address

Submarine Squadron 12
Box 70, Building 87
Naval Submarine Base New London
Groton, CT 06349-5200

CSS 12 Logo



The mission of COMSUBRON Twelve is to provide attack submarines that are ready, willing, and able to meet the unique challenges of undersea combat and deployed operations in unforgiving environments across the globe.



Commodore – Capt. Thomas P O’Donnell
Deputy for Operations – Capt. Jason M. Deichler
Deputy for Training – Cmdr. Andrew Hart
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