After serving in Toulon with the 7th and later 5th submarine squadrons, in 1937 Rubis was transferred to Cherbourg. During the Norwegian campaign, in May 1940, she laid mines off the Norwegian coast; her mines claimed four Norwegian vessels in May and June, and a further three merchantmen in July. At the time of the French surrender on June 22, 1940, she was in the port of Dundee, Scotland in the United Kingdom, where she promptly joined the Free French Forces.at that time she was commanded by Capitaine de Corvette Georges Cabanier