 However, according to Mary Shelley's testimony, Shelley changed it to "Ariel", which annoyed Byron, who forced the painting of the words "Don Juan" on the mainsail.The vessel, an open boat, was custom-built in Genoa for Shelley.It did not capsize but sank; Mary Shelley declared in her "Note on Poems of 1822" (1839) that the design had a defect and that the boat was never seaworthy.