Manby (c.1766-1834) was a member of the expedition to the Pacific Ocean commanded by Capt. George Vancouver. He left England as master's mate and returned as acting lieutenant. He made a voyage to the Arctic in 1808 and lived the rest of his life in his native Norfolk. He was promoted to the rank of rear-admiral in 1825.

The journal gives an account of the Vancouver expedition, which left England on 1 April 1791 and reached Australia by way of the Cape of Good Hope. After surveying part of the Western Australian coast, the Discovery and Chatham sailed for New Zealand and then Tahiti. The island of Rapa was discovered on 22 December 1791. From Tahiti the two ships sailed for Hawaii and then to the north-west coast of America. They visited Hawaii a second time early in 1793. The journal ends about 16 months before the Vancouver expedition returned to England.