AETILLEEY IN COAST DEFENCE. 
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units, each under a commander who will have, in action, a definite 
task to perform, which will usually be the defence of a certain portion 
of the water area; for instance, an entrance to the harbour or a bay 
from which an enemy might endeavour to bombard a dockyard, or to 
effect a landing, &c. Next, an economical but efficient scheme for 
manning the various guns and works of each unit must be drawn up. 
The largest tactical unit is termed a “ Section,” and its commander 
a “ Section Commander.” This officer may be of any rank and arm, 
and if not an artillery officer will have on his staff the “ Section 
C.R.A.,” who will command that arm. 
A “ Section ” consists of such forts and batteries as bear on the 
area which the Section Commander has to defend; the principle on 
which the fortress is divided being that each Section Commander 
should only have to control one distinct action at a time. 
There would also be mine-fields, coast defence vessels, &c., under his 
control; these latter to provide the power of counter-attack on the 
water, the artillery defence being necessarily passive. 
The next tactical unit is the “Fort” under a “Fort Commander.” It 
must be understood that the tactical meaning of the term “ fort ” 
includes not only closed works, but any battery, or group of batteries 
or works, which, for purposes of fire control, are placed under one 
command. Just as a Section Commander should usually only have to 
control one action at a time, that is to fight an enemy’s squadron 
attempting one definite object; so the Fort Commander, as a rule, 
would have to fight only one of the enemy’s vessels at a time ; conse¬ 
quently the guns placed under his command will all approximately be 
able to be brought to bear on one objective, not necessarily at the 
same moment, but at any rate consecutively. The Section and Fort 
Commanders are in an analagous position to the officer in command of 
a squadron and the Captains of the ships of that squadron, the O.C. 
of the squadron exercising tactical control over his ships and directing 
them against the proper objectives, as the Section Commander does 
with his forts; while the Captains of ships and Fort Commanders 
fight their ships or forts to the best advantage against the objectives 
pointed out to them. 
The next lower tactical unit is the “ Group ” under a “ Group 
Officer.” A group consists of such a number of guns as from their 
position can be conveniently supervised and commanded by one officer. 
The guns of each group must not be too many in number, therefore, 
or too far apart; each group must consist entirely of guns which can 
be brought to bear on the same objective; and should be of the same 
nature and calibre; and at the same height, approximately, above sea 
level. 
The group is the ultimate tactical unit, its guns being always fought 
at the same objective ; they must, therefore, all be able to bear on one 
spot or some will always be out of action, and if of different natures 
they will often require to be laid at different ranges to hit the same 
mark, and may require to use different projectiles against any given 
ship, thus making the fire discipline exceedingly complicated and likely 
to break down. 
