In northern waters, the Nationalists deployed España, Almirante Cervera, Velasco, and armed trawlers against the Republican destroyer José Luis Díez and submarines C-2 and C-5. José Luis Díez broke down often, C-2 could stay submerged for only two hours, and C-5's demoralized crew sheltered in a railway tunnel during air raids. C-5 later disappeared under disputed circumstances; postwar evidence suggested that its pro-Nationalist commander may have sunk it deliberately. After gaining autonomy in October 1936, the Basque authorities formed their own force from armed deep-sea trawlers and fishing boats equipped for minesweeping. Experienced fishermen served as "volunteers of the sea," giving Bilbao a local maritime force built for patrol and mine clearance amid political and material strain.
Chapter · 13:26-16:03
The Basque auxiliary navy filled a Republican gap
Poor reliability and divided loyalties in Republican units led the autonomous Basque authorities to organize armed deep-sea trawlers and minesweepers for northern Spain.