On June 18, 2023, the Titan submersible was about 90 minutes into its two-hour descent to the Titanic wreckage at the bottom of the Atlantic Ocean when it lost contact with its support ship. This break in communication set off a frantic search for the tourist submersible and five passengers on board, located about two miles below the ocean’s surface.

Deep-ocean search and recovery is one of the many missions of military services like the U.S. Coast Guard Office of Search and Rescue, and the U.S. Navy Supervisor of Salvage and Diving. For this mission, the longest delays came from transporting search-and-rescue equipment via ship to the area of interest, and comprehensively surveying that area. A search operation on the scale of that for Titan—which was conducted 420 nautical miles from the nearest port and covered 13,000 square kilometers, an area roughly twice the size of Connecticut—could take weeks to complete.

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