The son of an Irish actor and author, he was apprenticed to a coach painter at the age of twelve, but went to sea 1808-16. In 1816 he settled in London where he became a scene painter, working in 1822 with his friend David Roberts (q.v.) at the Theatre Royal, Drury Lane. In 1820 he exhibited his first paintings at the Royal Academy and the British Institution. By 1835, when he was elected a Royal Academician, he had abandoned his career as a scene painter and was already established as the leading British marine artist of his time, known especially for his convincing depictions of stormy seas. He made many European tours after 1823. For Charles Dickens, a close friend, he designed book illustrations and sets for his amateur theatricals.