Rous was promoted to post-captain on 25 April 1823, and from July 1825 commanded in the East Indies. He visited Australia, and in April 1827, organised Sydney's first regatta. In August 1828, he explored the Tweed, and he discovered, named and explored the Richmond River, both in northeastern New South Wales. The area between these rivers is known as Rous County, but counties in Australia are not widely known and are mainly used for cadastral purposes. While in Moreton Bay he named the Rous Channel, Dunwich, and Stradbroke Island, after his family titles and influenced the naming of Ipswich, Queensland.