of all Naval warfare must naturally rest with those who are
serving afloat, but it is only just to the Naval officers and others who
did such fine work at the Admiralty in preparing for the sea effort,
that their share in the Navy's final triumph should be known. The
writing of this book appeared also to be the only way in which I could
show my keen appreciation of the loyalty and devotion to duty of the
Naval Staff, of the many clever, ingenious and audacious schemes
developed and carried through for the destruction of submarines and the
safeguarding of ocean-borne trade, and of the skilful organization which
brought into being, and managed with such success, that great network of
convoys by which the sea communications of the Allies were kept open.
The volume shows how the officers who accompanied me to the Admiralty
from the Grand Fleet at the end of 1916, in association with those
already serving in Whitehall and others who joined in 1917, with the
necessary and valuable assistance of our comrades of the Mercantile
Marine, gradually produced the measures by which the Sea Service
conquered the gravest danger which has ever faced the Empire.

There were at times inevitable set-backs as the enemy gained experience
of our methods, and new ones had then to be devised, and we were always
most seriously handicapped by the strain imposed upon the Fleet by our
numerous military and other commitments overseas, and by the difficulty
of obtaining supplies of material, owing to the pre-occupation of our
industries in meeting the needs of our Armies in equipment and
munitions; but, generally speaking, it may be said that in April, 1917,
the losses reached their maximum, and that from the following month and
onwards the battle was being slowly but gradually won. By the end of the
year it was becoming apparent that success was assured.

The volume describes the changes carried out in the Admiralty Staff
organization; the position of affairs in regard to submarine warfare in
the early part of 1917; and the numerous anti-submarine measures which
were devised and brought into operation during the year. The
introduction and working of the convoy system is also dealt with. The
entry of the United States of America into the war marked the opening of
a new phase of the operations by sea, and it has been a pleasure to give
particulars of our cordial co-operation with the United States Navy. The
splendid work of the patrol craft and minesw