Iona was a schooner of 104 tons built by Bow, McLachlan of Paisley in 1920. She was 132' 9" long, had a breadth of 21' 7" and a draught of 11'. Her engines produced 95 h.p. Her signal letters were M.J.W.G. She was originally named Volo and was owned by William Bow and was registered in Glasgow. In 1929, she was sold to Lord Maclay and her name was changed to Iona. Then in 1935 she was sold to A. Smith-Bingham and H. Rolfe Owen who remained owners of the vessel until 1937 when she was sold to C. Treherne Thomas. In 1939 her ownership changed to the Belfast Harbour Commissioners and port of registry became Belfast. During World War II she was acquired by His Majesty's Government. In 1948, she was bought by Doris Houillon who subsequently renamed her Porcupine.

The vessel was finally broken up in 1952.