The experience that became the subject of his 1840 novel Two Years Before the Mast started on August 14, 1834. That day, aboard the brig Pilgrim, Dana left the port of Boston on the way to California. As he described:
The fourteenth of August was the day fixed upon for the sailing of the brig Pilgrim on her voyage from Boston round Cape Horn to the western coast of North America... I had undertaken [the voyage] from a determination to cure, if possible, by an entire change of life, and by a long absence from books and study, a weakness of the eyes, which had obliged me to give up my pursuits, and which no medical aid seemed likely to cure.
The change in young Dana's life was extreme — and sudden. His family was a well-known (and well-off) one. An ancestor, Francis Dana, had been a member of the Continental Congress and Chief Justice of the Massachusetts Supreme Court. His father (and namesake) was an accomplished poet, novelist, and somewhat controversial literary critic and editor. Dana, Jr. left the ranks of Harvard students, tossing aside his "tight dress coat, silk cap, and kid gloves" in exchange for "loose duck trowsers, checked shirt and tarpaulin hat of a sailor." Despite his attempts to look like "a jack tar... as salt as Neptune himself," he was soon recognized as a "landsman."
By the end of his voyage, he was a landsman no more. He did not return to Boston until September 1836. Thereafter, his eye troubles did not seem to bother him. Years later, he sailed to Europe with friends — a trip which reinforced how much he loved his own country (though he ultimately died in Rome).
His novel about his two years at sea is still moderately well-known. Dana Point, California is named after him. The Pilgrim has been recreated and an annual regatta also celebrates the author.