This is coolbert:
"At Paris, during a state dinner the French Minister of Marine leans close to the Japanese Ambassador and whispers that France and Japan must stand to the last on the submarine question." - - from "The American Black Chamber" by H.O. Yardley.
The "submarine question". An item on the agenda of the Washington Conference .
Treaty negotiations that resulted in the Washington Naval Treaty.
A naval treaty that restricted the number of capital ships the signatories to the treaty were allowed to have. When I speak of capital ships, I am thinking battleships and heavy cruisers. The significant striking force of all self-respecting navies the world over.
"The Washington Naval Treaty, also known as the Five-Power Treaty, limited the naval armaments of its five signatories: the United States, the British Empire, the Empire of Japan, the French Third Republic, and the Kingdom of Italy."
"This burst of capital ship construction kindled fears of a new naval arms race, similar to the Anglo-German Dreadnought race leading up to World War I."
A treaty that resulted in successful negotiations and signing thereof by the major powers of the world. CONFINED TO THE RESTRICTION OF SURFACE VESSELS!!
DID NOT INCLUDE SUBMARINES AMONG THE RESTRICTED WARSHIPS!!
"The Washington Naval Treaty had placed strict limits on naval construction by the major naval powers, but submarines had been omitted."
The French in particular, took advantage of the treaty exception to the "submarine question" by constructing a naval warship of an unique class. The underwater cruiser.
A SUBMARINE ALSO CAPABLE OF ENGAGING THE ENEMY IN SURFACE COMBAT. HAD INTEGRAL NAVAL GUNS OF LARGE SIZE. ALSO CARRIED RECONNAISSANCE AIRCRAFT OF THE FLOAT PLANE VARIETY.
This was the French Navy class of underwater cruiser Surcouf (N N 3):
"Surcouf was designed as an "underwater cruiser", intended to seek and engage in surface combat. For reconnaissance, she carried an observation float plane in a hangar built abaft of the conning tower; for combat, she was armed with 12 torpedo tubes and a twin 203mm/50 Modèle 1924 guns [that is dual 8 inch guns for those of you that are metrically challenged] in a watertight turret forward of the conning tower."
Prior to the Surcouf, the British too had "tinkered" with the idea of an underwater cruiser.
* HM Submairne X1.
"HM Submarine X1 was, conceived and designed as a submersible commerce raider for the Royal Navy . . . She was larger than any other submarine previously built and besides her six 21-inch bow torpedo tubes she carried two twin 5.2 inch gun turrets"
* HMS M2.
"HMS M2 was a Royal Navy aircraft-carrying submarine . . . she was armed with a single 12-inch (305 mm) gun as well as torpedo tubes."
[able to carry aircraft too. Those planes had an offensive capability? A combination of triple threat. A conventional submarine, surface attack, or aerial assault!]
The role of the underwater cruiser was strictly limited? Surprisingly so? A naval warship designed to do it all could not any of them [combat operations] well?