dditional tremendous advantage of being able to hide by submergence. To be completely successful, it must operate in flotillas of hundreds in waters that are opaque to aërial observation. Germany has but a limited number of these submersibles, otherwise she would be able to crush the Allied commerce.
The ideal submersible commerce-raider should be a vessel of such displacement that she could carry a sufficient number of large guns in her superstructure to enable her to fight off the attack of surface destroyers and the smaller patrol craft. She should be capable of cruising over a large radius at high speed, both on the surface and submerged. The supersubmersible flotillas should comprise fifty or sixty of these units. The attack on the trade routes should be made by a number of flotillas operating at different points at unexpected times. To-day Germany has concentrated her submarine war particularly in the constricted waters about England. It is here that the shipping is most congested, and th