Midget submarines in a Great Lakes naval contest

What kind of submarine warfare might develop during a Great Lakes naval arms race?

Small X-craft-like submarines carrying one or two torpedoes would suit the confined lakes and be difficult to counter.

A Great Lakes submarine campaign would have to adapt to confined and often shallow operating areas. Very small boats resembling British X-craft would fit better than full-size fleet submarines. Even one or two torpedoes would give such craft a serious ambush capability. Their small size would also make detection and clearance unusually difficult in the lakes' restricted waters.