USS Michigan..

The Ohio class is a class of nuclear-powered submarines used by the United States Navy. The United States has 18 Ohio-class submarines:

• 14 nuclear-powered SSBNs, each armed with 24 Trident II SLBMs; they are also known as "Trident" submarines, and provide the sea-based leg of the nuclear triad of the United States strategic nuclear weapons arsenal
• 4 nuclear-powered SSGNs, each capable of carrying 154 Tomahawk cruise missiles with conventional warheads

The 14 Trident II SSBNs together carry around fifty percent of the total U.S. strategic warhead inventory. The exact number varies in an unpredictable and highly classified manner, at or below a maximum set by various strategic arms limitation treaties. Although the missiles have no pre-set targets when the submarine goes on patrol, the platform, when required, is capable of rapid targeting using secure and constant at-sea communications links. The Ohio class is the largest type of submarine ever constructed for the U.S. Navy, and are second only to the Russian Typhoon-class in displacement and size (the new Russian Borei class submarine has bigger displacement when submerged, but not when surfaced). more...