Guns placed of US submarines according to the Dutch magazine Marineblad dated 1915-1916 no. 3

An item referred to the magazine Schiffbau no. 23 reporting that the large type of American submarines with 10,2cm and the smaller types of the M and N-classes with 7,6cm guns were fitted out for use as anti aircraft guns. Due to the limited space was the calibre smaller as L/50.