From 1 October 1800 to 23 June 1803, Hamelin captained the bomb ship
Naturaliste, along with Captain
Nicolas Baudin on
Géographe, on a
scientific expedition exploring the South Seas. This voyage was intended as a scientific exploration of
New Holland and the charting of the as yet unknown southern coastline. There were no instructions from the French government to claim any land in the name of France. This expedition returned to France the largest collection of plants animals and seeds from New Holland and
Timor that Europe had ever seen, including two short-legged emus from King Island who lived out their days in Josephine's garden. Baudin rejected ideas amongst his crewmen that they should found a settlement there, and he wrote letters back home to this effect. A party of Hamelin's men discovered a
plate, left by
Willem de Vlamingh in 1697, which had in turn replaced an earlier plate left by
Dirk Hartog in 1616. Hamelin's men initially removed the plate but it was returned on his orders and left intact until a later visit by
Louis de Freycinet in 1818. De Freycinet was on Hamelin's 1801 crew. On his return to France, Hamelin was promoted to
captaine de vaisseau (captain), and oversaw the weaponry of the fleet intended for
Napoleon's planned invasion of the United Kingdom.
Mauritius , where Hamelin was captured In July 1806, Hamelin took command of the frigate
Vénus at
Le Havre. He set sail for
Isle de France, capturing four British ships along the way. In March 1809,
Vénus entered
Port Napoléon at the start of the
Mauritius campaign of 1809–1811 between France and Britain over French colonies in the Indian ocean. On 26 April, after orders from the governor of Ile de France to leave, he sailed off, having under his command
Vénus, the frigate
Manche, the brig
Entreprenant, and the schooner
Créole. He visited
Foulpointe on the east coast of
Madagascar. Besieged by local Madagascan tribesmen, he sailed for the
Bay of Bengal. On the way there,
Vénus captured the
East India Company (EIC) armed ship
Orient on 26 July. Hamelin then turned east in search of more British shipping to attack, capturing several small merchantmen off the
Nicobar Islands and destroying the EIC factory at
Tappanooly on 10 October. On the return voyage to Mauritius, he captured three EIC
East Indiamen in the
action of 18 November 1809. On his return trip, Hamelin captured several more British ships, until he encountered
HMS Ceylon on 17 September.
Ceylon was captured, but the next day a British frigate squadron
captured both Ceylon and
Vénus.
Hero's return Hamelin remained a prisoner of the British for the rest of the year. He was however released in a prisoner exchange, and on his return to France in February 1811 Hamelin was presented to
Napoleon and made a
''Commandeur de la Légion d'honneur, created a
Baron of Empire, raised to the rank of
counter admiral and named commander of a division of the squadron under the orders of Admiral
Édouard Thomas Burgues de Missiessy. In April 1818 he moved to
Toulon as general major of the navy, a post that he occupied until 18 May 1822. In early 1823, he was bestowed the rank of Grand Officer de la Légion d'Honneur''. In 1832 Baron Hamelin was appointed Inspector General of Marine Crews, and in 1833 he was named Director of Marine Cartography. He retired shortly after, and died in Paris. His nephew was Admiral
Ferdinand-Alphonse Hamelin. ==Legacy==