'catfish') were a series of submarines built for the Imperial Russian Navy in 1904–1907.

They were designed by the Electric Boat Company and ordered in the 1904 emergency programme at the time of the Russo-Japanese War.

The vessel was sold and delivered to Russia in sections and re-assembled in St.

[1] In July 2015 it was reported that the wreck of Som (Сом) had been located in Swedish waters.

[2][3] Media related to Som class submarine at Wikimedia Commons