USS Helena (SSN 725), a Los Angeles-class nuclear attack submarine is the 37th ship of the class, and is the fourth United States Ship to bear the name of the capital city of the state of Montana. Her keel was laid on September 16, 1984 at General Dynamics Corporation, Electric Boat Division, Groton, Connecticut. She was launched June 28, 1986 and was commissioned on July 11, 1987.

Following a successful six-month deployment in the Seventh Fleet area of operations, USS Helena returned to San Diego in mid-December 2003. Upon their return, she was awarded the 2003 Commander, Submarine Squadron Eleven Battle Efficiency "E" and Supply Blue "E". While on deployment, the submarine participated in various exercises with U.S. assets and allied countries, including a multi-national exercise with Australia. In addition to its numerous operating commitments she was able to enjoy port visits in South Korea, Japan, Australia, Guam and Saipan.

September 18, 2005 SSN 725 returned to Naval Base Point Loma, California, after a scheduled six-month deployment in the western Pacific.

January 10, 2006 USS Helena entered the Navy’s only floating dry dock, Arco, in Naval Base Point Loma, for a routine scheduled maintenance.

May 16, 2007 Commodore of Submarine Squadron 11, Capt. Paul N. Jaenichen, relieved the commanding officer of USS Helena, Cmdr. William A. Schwalm, due to a loss of confidence in his ability to command. Cmdr. Daryl L. Caudle will serve as the temporary CO.

December 14, SSN 725 is currently conducting a submarine familiarization in the Pacific Ocean, as part of USS Ronald Reagan CSG.

January 30, 2008 USS Helena departed homeport for a western Pacific deployment.

February 24, The San Diego-based attack submarine recently departed Sasebo, Japan, after a four-day port call.

July 30, USS Helena, commanded by Cmdr. Daniel Brunk, returned to San Diego after a six-month underway period.

February 27, 2009 SSN 725 departed homeport to participate in Ice Exercise (ICEX) 2009 in the Arctic Ocean. USS Annapolis (SSN 760) will also be part of the exercise.

April 17, USS Helena returned to San Diego after a 50-day voyage to the Arctic Ocean. The Los Angeles-class submarine operated approximately 200 miles from the north coast of Alaska, near Prudoe Bay, to train and test weapons and different warfare tactics in the Arctic region.

September 2, The Helena arrived at Portsmouth Naval Shipyard in Kittery, Maine, for extended maintenance including several system upgrades over the next 18 months.