advance route of the enemy generally favor the
lanes can disclose the location of your positions to an
defending force. Obstacles parallel to the advance of the
observant enemy.
enemy may favor the enemy by protecting his flanks,
Observation and fields of fire are so closely related
although the obstacles may also limit his lateral
that they are considered together. They are not
movement. The effectiveness of an obstacle must be
synonymous, but fields of fire are based on observation,
carefully examined. An obstacle by itself is rarely an
since the enemy must be seen to bring effective fire on
absolute block to military movement by a determined
him. These aspects are particularly important to the
enemy. A defender who puts full faith in an obstacle by
defender. The primary considerations for choosing a
itself stands the risk of being surprised by enemy
defensive position are maximum observation and long
movement over or through that obstacle. Maximum
fields of fire.
effectiveness is gained from an obstacle kept under
observation and fire.
COVER AND CONCEALMENT
COVER is shelter protection from enemy fire,
either natural or artificial. Geographical relief features,
An avenue of approach is a terrain feature or
drainage areas, cultural features, and other artificial
combination of features that offer a maneuvering unit a
shelters provide cover. Cover from flat trajectory fire is
suitable route of movement to their objective. The
best exemplified by the concept of reverse slope; that is,
desirable characteristics of an avenue of approach are
when there is a projection of relief, such as a hill,
listed below.
between you and the enemy. Cover must be considered
in relation to the types of fire encountered. For example,
EASE OF MOVEMENT toward the objective
a trench offers excellent protection against rifle fire, but
COVER and CONCEALMENT from the fire
only limited protection against mortar or artillery fire.
and observation of the defender
CONCEALMENT is protection from observation.
FAVORABLE OBSERVATION and fields of fire
Vegetation, cultural features, geographical relief
for the attacker
features, drainage areas, weather conditions, and
darkness can provide protection from observation.
Adequate ROOM FOR MANEUVER and
Frequently, you can obtain concealment by properly
dispersal by the attacking unit
evaluating and using just the terrain. At other times, you
You, as a defender, must pay particular attention to
may need artificial means (camouflage) in addition to
all avenues of approach. These approaches into your
natural, available concealment.
Seabee position represent potential weak spots in the
Concealment is the reverse concept of observation.
defense, and Seabees must be positioned to block and
Since the defender usually has the opportunity to choose
cover them effectively. As a defender, you must also
the ground he wishes to defend, he selects positions that
consider the use of these avenues of approach by your
take maximum advantage of natural cover and
own forces should you wish to launch a counterattack.
concealment, adding field fortifications and natural
concealment with camouflage to improve the position.
MAPS AND THE COMPASS
It is important that you judge your own cover and
concealment by looking at it from the point of view of
In a combat situation, your life may depend upon
a potential attacker.
your ability to read and use a map and compass. When
you are on a night patrol and become separated from the
OBSTACLES
rest of the patrol, you must find your way back to
friendly lines by yourself. This could be next to
Obstacles are obstructions that stop or divert troop
impossible without using a map that shows the
movement. Common natural obstacles of military value
approximate location of friendly forces. With a map and
include mountains, rivers, streams, lakes, marshes,
compass, you should be able to locate your position and
gullies, steep inclines, and heavily wooded areas.
then follow a route to your destination.
Common artificial obstacles include minefield, cut and
In this phase of our discussion, we discuss military
falls, trenches, antitank ditches, roadblocks, barbed wire,
blown bridges, and road craters. The proper evaluation
maps first. Then, special attention is given to topics that
of natural obstacles permits the most effective use of
should help you to read maps accurately and
artificial obstacles. Obstacles perpendicular to the
intelligently. Later, we discuss the use of a lensatic
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