n anticipation of the
unrestricted warfare, since none of their larger boats was operating in
our waters between these months; this fact had a considerable bearing on
the problem.

As events turned out it would appear either that the training given was
insufficient or that the German submarine officer was lacking in
enterprise.

There is no doubt whatever that had the German craft engaged in the
unrestricted submarine warfare been manned by British officers and men,
adopting German methods, there would have been but few Allied or neutral
merchant ships left afloat by the end of 1917.

So long as the majority of the German submarine attacks upon shipping
were made by gun-fire, the method of defence was comparatively simple,
in that it merely involved the supply to merchant ships of guns of
sufficient power to prevent the submarine engaging at ranges at which
the fire could not be returned. Whilst the _method_ of defence was
apparent, the problem of _supplying_ suitable guns in sufficient numbers
was a very different matter. It involved arming all our merchant ships
with guns of 4-inch calibre and above. In January, 1917, only some 1,400
British ships had been so armed since the outbreak of war.

It will be seen, therefore, that so long as ships sailed singly, very
extensive supplies of guns were required to meet gun attack, and as
there was most pressing need for the supply of guns for the Army in
France, as well as for the anti-aircraft defence of London, the prospect
of arming merchant ships adequately was not promising.

When the enemy commenced unrestricted submarine warfare attack by
gun-fire was gradually replaced by attack by torpedo, and the problem at
once became infinitely more complicated.

Gun-fire was no longer a protection, since the submarine was rarely
seen. The first intimation of her presence would be given by the track
of a torpedo coming towards the ship, and no defence was then possible
beyond an endeavour to manoeuvre the ship clear of the torpedo. Since,
however, a torpedo is always some distance ahead of the bubbles which
mark its track (the speed of the torpedo exceeding 30 knots an hour),
the track is not, as a rule, seen until the torpedo is fairly close to
the ship unless the sea is absolutely calm. The chance of a ship of low
speed avoiding a hit by a timely alteration of course after the torpedo
has been fired is but slight. Further, the only difficulty experienced
by a submarine in h