 The months following this were unfruitful, however, as the U-boat Arm changed its tactics to operate in the shallow inland waters around Britain, using the "schnorkel" to remain submerged for entire patrols.This created a different set of tactical problems, requiring different tactics of the escorts.In 1945 "Loch Fada" and "Loch Killin" were transferred, to be replaced by , , and .