Although the design proved moderately successful, the submarine did not attract German naval attention.

[1] It was shipped from Kiel to Liepāja by railway, together with a team of German engineers to train the Russian crew, and was commissioned at Kronstadt on 21 August 1904.

It was then sent via the Trans-Siberian Railway to Vladivostok, arriving on 29 September, and joined the Siberian Flotilla on 2 October, becoming the first Russian submarine in the Pacific.

Forel continued to operate out of Vladivostok after the war; however, by 1908 it was considered obsolete and was re-classed as a training vessel.

Vice Admiral Ivan Grigorovich authorized it to be returned to Liepāja for repairs, but shipping was never implemented.