The Imperial Russian Navy operated out of Kronstadt, next to St. Petersburg. Well before sending the Nadezhda and Neva into the Pacific in 1803, the empire had Pacific ports like Okhotsk, accessible by land from Yakutsk, as well as several in Kamchatka, generally reached by sea. Okhotsk had a shipyard, as well as a commandant who was tried by the Admiralty (thanks @PieterGeerkens), but I can't tell yet if the Kamchatka commandants were in the navy too.
During Catherine the Great's rule (1762-1796), to which military force and commandant were the Kamchatka detachments in Bolsheretsk and Nizhnekamchatsk responsible?