and to execute the measures that the calculations show
to be required.

_Static Defense of the Coast_.--But besides the mobile fleet which
is a nation's principal concern, strategy requires that for certain
points on the coast, where large national and commercial interests
are centred, arrangements shall be made for what may be termed a
"static defense," by vessels, mine-fields, submarines, aircraft,
etc., assigned as permanent parts of the defense of these points,
analogous to forts on the land. The naval activities of this species
of defense will centre on the mine-fields which it is a great part of
their duty to defend. To guard these, and to get timely information
of the coming of any hostile force or raiding expedition, strategy
says we must get our eyes and ears well out from the land. To do
this, water craft and aircraft of various kinds are needed; and
they must be not only sufficiently numerous over each area to scout
the waters thoroughly, but they must be adapted to their purpose,
manned by adequate and skilful crews, and organized so as to act
effectively together.

The work of this patrol system is not to be restricted, however,
to getting and transmitting information. Certain of the craft must
be armed sufficiently to drive off hostile craft, trying to drag
or countermine the defensive mine-fields; some must be able to
add to the defensive mine-fields by planting mines, and some must
be able to pilot friendly ships through the defensive mine-fields;
others still must be able to countermine, drag, and sweep for any
offensive mines that the enemy may plant.

Vessels for this patrol work do not have to be very large; in fact,
for much of the work in the mine-fields, it were better if they
were small, by reason of the ability of small vessels to turn in
restricted spaces.

It would seem that for the patrol service, the vessels of the Revenue
Marine and Lighthouse Service (coast guard) are ideally adapted;
but, of course, there are only a few in total. These would have to
be supplemented by small craft of many kinds, such as tugs, fast
motor-boats, fishing-boats, and trawlers. To find men competent
to man such vessels and do the kind of work required would not be
so difficult as to get men competent to man the more distinctive
fighting ships. Good merchant sailors, fishermen, and tugboat men
would fit into the work with considerable ease, and in quite a
short time. Strategy declares, however, that a coas