He served on the Adriatic Sea (1848-1849) and resigned in 1860 to join the French Navy commanding the Zenobia and later the Asmodeus.
In 1865 he commanded the frigate Regina from Naples to Montevideo and from there the corvette Magenta on a voyage around the world.
The ship also carried the naturalists Prof. Enrico Hillyer Giglioli and Filippo de Filippi who collected and described various zoological specimens including the Trindade petrel which was named after Arminjon as Pterodroma arminjoniana.
He resigned in 1877 and spent his time studying agriculture and experimenting with applied chemistry on his lands in the Piedmont.
In 1882 on the occasion of the fourth centenary of Christopher Columbus' service to Isabella of Castile, Admiral Arminjon received the Grand'Croix of Spanish Naval Merit from King Alfonso XII of Spain.