guide-ship's angry signals), we erred in reserving a margin that
retarded the full efficiency of a convoy. Our commodores had no small
difficulty in conforming to the date of their convoy's arrival at a
rendezvous. The 'cruising speed' of ten knots, that we had so blithely
taken up when sailing from an oversea port, frequently toned down to an
average of eight--with all the consequent derangement of the destroyers'
programme at the home end; a declared nine-knot convoy would romp home
at ten, to find no escort at the rendezvous.

In time, we adjusted our estimate to meet the new demands. Efforts of
the Ministry of Shipping to evolve an order in our voyaging that would
reduce irregularities had good results. The skilfully thought-out
appointment of the ships to suitable routes and trades had effect in
producing a homogeneity that furthered the employment of our resources
to the full. The whole conduct of our seafaring speedily came within the
range of governmental control, as affecting the timely dispatch and
arrival of the convoys. The quality of our fuel, the state of the hull,
competence of seamen, formed subject for close investigation. The rate
of loading or discharge, the urgency of repairs and refitment, were no
longer judged on the note of our single needs; like the states of the
weather and the tide, they were weighed and assessed in the formula that
governed our new fleet movements.

The system of convoy protection had instant effect in curbing the
activities of the U-boats. They could no longer work at sea on the lines
that had proved so safe for them and disastrous for us. To get at the
ships they had now to come within range of the destroyers' armament.
Hydrophones and depth-charges reduced their vantage of submersion. The
risks of sudden rupture of their plating by the swiftly moving keel of
an escorting vessel did not tend to facilitate the working of their
torpedo problem. In the coastal areas aircraft patrolled overhead the
convoys, to add their hawk-sight to the ready swerve of the destroyers.
The chances of successful attack diminished as the hazard of discovery
and destruction increased. Still, they were no fainthearts. The German
submarine commanders, brutal and hell-nurtured, are no cowards. The
temptation of a massed target attracted them, and they sought, in the
confusion of the startled ships, a means of escape from the destroyers
when their shot into the 'brown' had run true.

Convoy has added