The Greek vessel Sink, carrying 6,000 tonnes of copper, sank on Friday while carrying an unidentified cargo in a shallow area off the island of Crete.
It is the first time a vessel carrying copper has sunk in more than two decades.
The vessel sank about 300 metres (1,100 feet) from the shoreline of the island, which is a popular tourist destination for tourists and Greek residents.
The rescue operation began at 7:30 a.m. local time (0330 GMT) after the ship’s captain reported a low visibility.
The Coast Guard dispatched two ships to help.
They found the vessel about 600 metres (2,000 feet) below the surface, according to Greek media reports.
The cargo was not lost, the Coast Guard said in a statement.
The ship’s crew and the passengers were uninjured.
The coast guard said it has been trying to contact the crew of the vessel to ask them to turn back and help search for survivors.
The captain, a Greek citizen, has been arrested and is currently in custody.
Greek officials said the ship was carrying about 6,300 tonnes of the precious metal, which has been widely exported in the country.
The International Copper Council, a global trade group, has estimated that Greece exported around 2,400 tonnes of Copper in 2015.