WASHINGTON — The vessel that went missing Sunday in the North Atlantic while exploring the Titanic's wreckage is a submersible not a submarine, and there is a key difference.
The Titan, with five people on board, remained missing Tuesday even as an international search and rescue effort was underway.
The National Oceanic and Atmospheric Administration explains the difference. A submarine has enough power to leave port and come back to port under its own power.
But a submersible has more limited power and range. It needs a mother ship from which to launch, to return to, and for support and communications.
The Titan's mother ship is the Polar Prince, a former Canadian Coast Guard icebreaker.
Where is the Titanic wreckage?
The Titanic was on its maiden voyage from Southampton, England, to New York City when it hit an iceberg off Newfoundland in the North Atlantic on April 15, 1912. The luxury ocean liner sank within hours, killing about 1,500 people.
It was at the time the world's largest ocean liner and was supposed to be virtually unsinkable. Its passengers included some of the world's most wealthy and famous. And in the aftermath, the world heard remarkable stories of heroism and bravery by the crew and passengers.
The wreck, discovered in 1985 with an underwater camera, lies some 12,500 feet under the sea, about 435 miles off the coast of Canada.