Photo: Paul Vinten/iStock

On March 23, the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Navy ended a 95-year-old mystery when they announced the discovery of the USS Conestoga, a Navy tugboat that disappeared in 1921 with 56 people on board while en route from San Francisco to Pearl Harbor, Hawaii.

Unconfirmed sightings and a drifting lifeboat with the letter “C” that was found shortly after the Conestoga vanished led to intense searches near Hawaii and Mexico, but it turned out the ship barely made it 24 hours from San Francisco before sinking in a storm. The wreck was initially located in 2009 as a sonar target in the Greater Farallones National Marine Sanctuary, during a survey of the many shipwrecks in the area. But NOAA didn’t examine it closer until 2014, and it took a year to confirm its identity. That happened last October, and government officials spent the next six months notifying as many surviving family members of the crew as possible.

Jim Delgado, NOAA’s director of maritime heritage, worked on the Conestoga search and has spent nearly 40 years investigating lost ships around the world. “The simple reality is that even today, ships go missing all the time without a trace,” Delgado says. To wit: UNESCO estimates there are three million ships sitting on the bottom of the ocean, and Delgado theorizes we have no clue what happened to at least one million of them, nor do we know where they are.

We asked Delgado to help us sort through that million and compile this list of the 10 most iconic missing ships waiting to be discovered.