Calypso was originally a wooden-hulled minesweeper built for the British Royal Navy by the Ballard Marine Railway Company of Seattle, Washington USA.She was a British Yard Minesweeper BYMS , laid down on 12 August, 1941 with the yard designation BYMS-26 and launched on 21 March, 1942. She was commissioned into the Royal Navy in February 1943 as HMS J-826 and assigned to active service in the Mediterranean Sea, reclassified as BYMS-2026 in 1944, laid up at Malta and finally struck from the Naval Register in 1947.
After WW2 she became a ferry between Malta and the island of Gozo, and was renamed after the nymph Calypso, whose island of Ogygia was mythically associated with Gozo.
The Irish millionaire Thomas Loel Guinnes bought Calypso in 1950 and leased her to Cousteau for a symbolic one franc a year. Cousteau restructured and transformed her into an expedition vessel and support base for diving, filming and oceanographic research.
On 8 January 1996, a barge accidentally rammed Calypso and sank her in the port of Singapore. On 16 January, she was raised by a 230-foot crane, patched and pumped dry before being put in shipyard.