Shelley and Edward Williams had wanted to begin sailing for some time, and Trelawny used his naval experience to help them make plans. Together they decided to have an American-style schooner constructed; he had often observed this type of boat during his time in the navy. After Shelley and Williams had constructed their boat, the "Don Juan", Trelawny was hired by Byron to be the Captain of his vessel, the "Bolivar". Trelawny also moved into a room in Byron's mansion at that time. Trelawny's friend Daniel Roberts designed and supervised the construction of both vessels. The construction of the "Bolivar" cost £750, a sum which Byron found irritatingly high.