The Argonauta-class submarine was the first sub-class of the 600 Series of coastal submarines built for the Regia Marina during the 1930s. Some of these boats played a minor role in the Spanish Civil War of 1936–1939 supporting the Spanish Nationalists. Of the seven boats built in this class, only a single one survived the Second World War.
Argo was the lead ship of her class of two submarines ordered by the Portuguese government, but taken over and completed for the Regia Marina during the 1930s.
Velella was one of a pair of submarines ordered by the Portuguese government, but taken over and completed for the Regia Marina during the 1930s.
The Sirena-class submarines were the second sub-class of the 600 Series of coastal submarines built for the Regia Marina during the early 1930s. Of the dozen boats built of this class, only one survived World War II.
Ametista was the lead ship of her class of a dozen submarines, the second sub-class of the 600 Series of coastal submarines built for the Regia Marina during the early 1930s.
Anfitrite was one of a dozen Sirena-class submarines, the second sub-class of the 600 Series of coastal submarines built for the Regia Marina during the early 1930s.
Diamante was one of a dozen Sirena-class submarines, the second sub-class of the 600 Series of coastal submarines built for the Regia Marina during the early 1930s.
Galatea was one of a dozen Sirena-class submarines, the second sub-class of the 600 Series of coastal submarines built for the Regia Marina during the early 1930s. She played a minor role in the Spanish Civil War of 1936–1939 supporting the Spanish Nationalists.
Naiade was one of a dozen Sirena-class submarines, the second sub-class of the 600 Series of coastal submarines built for the Regia Marina during the early 1930s.
Nereide was one of a dozen Sirena-class submarines, the second sub-class of the 600 Series of coastal submarines built for the Regia Marina during the early 1930s.
Ondina was one of a dozen Sirena-class submarines, the second sub-class of the 600 Series of coastal submarines built for the Regia Marina during the early 1930s.
Sirena was one of a dozen Sirena-class submarines, the second sub-class of the 600 Series of coastal submarines built for the Regia Marina during the early 1930s.
Smeraldo was one of a dozen Sirena-class submarines, the second sub-class of the 600 Series of coastal submarines built for the Regia Marina during the early 1930s.
Topazio was one of a dozen Sirena-class submarines, the second sub-class of the 600 Series of coastal submarines built for the Regia Marina during the early 1930s. She played a minor role in the Spanish Civil War of 1936–1939 supporting the Spanish Nationalists.
Zaffiro was one of a dozen Sirena-class submarines, the second sub-class of the 600 Series of coastal submarines built for the Regia Marina during the early 1930s.
The Bandiera-class submarines were built for the Regia Marina during the late 1920s. They played a minor role in the Spanish Civil War of 1936–1939 supporting the Spanish Nationalists.
Argonauta was the lead ship of her class of seven submarines built for the Regia Marina during the early 1930s.
Serpente was one of seven Argonauta-class submarines built for the Regia Marina during the early 1930s.
The Mameli-class submarine was one of the first classes of the submarines to be built for the Regia Marina after the First World War. Some of these boats played a minor role in the Spanish Civil War of 1936–1939 supporting the Spanish Nationalists. Of the four boats built in this class, all but one survived the Second World War.
Pier Capponi was one of four Mameli-class submarines built for the Regia Marina during the 1920s.
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