On account of the immense theatre and the length and number of lines of communication, and the material deterioration resulting from three years' continuous operation in distant fields with inadequate base facilities, the strength of the naval forces is dangerously strained. This applies to all of the sea forces outside of the Grand Fleet. The enemy has six large and sixty-four small submarine mine-layers; the latter carry eighteen mines and the former thirty-four, also torpedoes and guns. All classes submarines for actual commission completed at a rate approaching three per week. To accelerate and insure defeat of the submarine campaign immediate active co-operation absolutely necessary. The issue is and must inevitably be decided at the focus of all lines of communications in the Eastern Atlantic, therefore I very urgently recommend the following immediate naval co-operation. Maximum number of destroyers to be sent, accompanied by small anti-submarine craft; the former to patrol designated high seas area westward to Ireland, based on Queenstown, with an advance base at Bantry Bay, latter to be an inshore patrol for destroyers: small craft should be of light draft with as high speed as possible but low speed also useful. Also repair ships and staff for base. Oil and docks are available but I advise sending continuous supply of fuel. German main fleet must be contained, demanding maximum conservation of the British main fleet. South of Scotland no base is so far available for this force. At present our battleships can serve no useful purpose in this area, except that two divisions of dreadnoughts might be based on Brest for moral effect against anticipated raids by heavy enemy ships in the channel out of reach of the British main fleet. The chief other and urgent practical co-operation is merchant tonnage and a continuous augmentation of anti-submarine craft to reinforce our advanced forces. There is a serious shortage of the latter craft. For towing the present large amount of sailing tonnage through dangerous areas sea-going tugs would be of great use. The co-operation outlined above should be expedited with the utmost despatch in order to break the enemy submarine _moral_ and accelerate the accomplishment of the chief American objective. It is very likely the enemy will make submarine mine-laying raids on our coast or in the Caribbean to divert attention and to keep our forces from the critical areas in the Eastern Atlantic through effect upon public opinion. The difficulty of maintaining submarine bases and the focussing of shipping on this side will restrict such operations to minor importance, although they should be effectively opposed, principally by keeping the Channel swept on soundings. Enemy submarine mines have been anchored as deep as ninety fathoms but majority at not more than fifty fathoms. Mines do not rise from the bottom to set depth until from twenty-four to forty-eight hours after they have been laid.