They did not appear there until May, 1918.

The moral effect of such action in 1917 would have been very great and might possibly have led to the retention in the United States of some of the destroyers and other small craft which were of such assistance in European waters in starting the convoy system.

Admiral Sims was himself, I think, anxious on this head.
When the Germans did move in this direction in 1918 it was too late; it was by that time realized in the United States that the enemy could not maintain submarines in sufficient numbers in their waters to exercise any decisive effect, although the shipping losses might be considerable for a time, and consequently no large change of policy was made.
As is well known, Admiral Sims, with the consent of the United States Navy Department, placed all vessels which were dispatched to British waters under the British flag officers in whose Command they were working.

This step, which at once produced unity of command, is typical of the manner in which the two navies, under the guidance of their senior officers, worked together throughout the war.

The destroyers operating from Queenstown came under Admiral Sir Lewis Bayly; Captain Pringle, the senior United States officer on the spot, whose services were ever of the utmost value, was appointed as Chief of the Staff to Sir Lewis Bayly, whilst on the occasion of Sir Lewis Bayly, at my urgent suggestion, consenting to take a few days' leave in the summer of 1917, Admiral Sims, at our request, took his place at Queenstown, hoisting his flag in command of the British and United States naval forces.