A search is on for a civilian submersible that went missing while trying to explore the Titanic. The wreck of the Titanic is under about 12,500 feet of water in the North Atlantic Ocean. The US Navy's submarine fleetVirginia-class sub USS North Dakota during sea trials in the Atlantic Ocean in August 2013. Reuters/US Navy HandoutThe United States Navy operates some of the most advanced and capable submarines ever to sail, commonly split into three operational categories: ballistic-missile subs, guided-missile subs, and attack subs. Guided-missile submarines are the same platforms as the Navy's boomers, but were converted to launch conventional munitions and deploy special-operations troops.

---

Persons: —, submersibles, Amanda Gray America's, Patrick Tyler's, Janes, Ashley, it's, HY Organizations: Service, OceanGate Expeditions, Polar, US Coast Guard, Reuters, US Navy, United States Navy, Los, Anadolu Agency, Washington Post, Naval Submarine Base, OceanGate Locations: Virginia, North Dakota, Ohio, Los Angeles, Angeles, Los, Amanda Gray America's Los Angeles, Tennessee, Bay, Georgia, America's Ohio