submarine

From http://www.generaldynamics.com/:

Defense industry contractor for shipbuilding and marine systems, defense systems, land and amphibious combat systems and munitions

From Wikipedia: General Dynamics:

General Dynamics Corporation is a U.S. defense conglomerate formed by mergers and divestitures, and as of 2008 it is the fifth largest defense contractor in the world. The company has changed markedly in the post-Cold War era of defense consolidation. The company has four main business segments: Marine Systems, Combat Systems, Information Systems and Technology, and Aerospace. The company's former Fort Worth Division manufactured the F-16 Fighting Falcon, the most-produced Western jet fighter, but that subsidiary was sold to Lockheed in 1993. GD reentered the airframe business in 1999 with their purchase of Gulfstream Aerospace.

From Wikipedia: Marconi Electronic Systems:

Marconi Electronic Systems (MES), or GEC-Marconi as it was until 1998, was the defence arm of The General Electric Company (GEC). It was demerged from GEC and acquired by British Aerospace (BAe) on November 30, 1999 to form BAE Systems. GEC then renamed itself Marconi plc.

MES exists today as BAE Systems Electronics Limited, a subsidiary of BAE Systems, but the assets were rearranged elsewhere within that company. MES-related businesses include BAE Systems Submarine Solutions, BVT Surface Fleet, BAE Systems Insyte and SELEX Sensors and Airborne Systems (now owned by Finmeccanica).