Except for a scene in Agatha's favorite story, The Heterodyne Boys and the Race to the West Pole, Submarines have so far had no place in the "canon", but according to the Secret Blueprints, England (of necessity, as much of the inhabited area is, in fact, submerged) makes extensive use of them.
At the end of the second novel, Wooster mentions that an English submarine could take Agatha from Paris to London.
A number of cards in The Works are for submarines, equal in fact to the number of airships. Furthermore, scoring some of each kind is a shortcut to victory. Although The Works is not styled after military action, it gives one the feeling that an eventual conflict between the Air (The Baron's Peace) and the Sea (England) for World Domination could be in the cards.
Possibly relevant outside informationEdit
Captain Nemo's is probably too obvious to mention, but perhaps not to make a comment to that effect.