Hull down

Crossing a crest or ridgeline is a dangerous manoeuvre for AFVs, as they are particularly exposed to enemy fire while silhouetted against the sky (skylined).

While cresting a steep slope, the thin armour on the front bottom of a tank's hull (below the thick glacis plate) can be exposed to fire.

If an antitank gunner has spotted the AFV, they may train their sights on it and wait for an easy shot while it moves forward.

Small armoured units (companies or platoons) make use of these tactics in co-ordinated fashion, when contact with the enemy is expected.

Lightly armed reconnaissance elements make much use of covered movement and stealth, while offensive units such as tanks move much more aggressively.

A vehicle with a relatively small range of gun depression may have to drive up onto an exposed crest or forward slope to be able to fire on lower ground to the front.

Notably, Soviet and Russian tanks after World War II have very low profiles, but pay for this advantage by having a poor range of gun depression.

This disadvantage was deemed acceptable, as Soviet tanks were designed to be used as an offensive weapon, fighting over flat terrain.

Newer Soviet tank models were equipped with an integral dozer blade, so given time, they could improve a hull-down position.

Soviet tactics also emphasize the use of tanks on the defence in the counterattack role, rather than engaging an enemy advance from prepared positions.

The turretless design was chosen to give it a low profile and thus increase protection, including in a hull-down position.

A ship at different distances
Leclerc tank in a hull-down position. Note the observation periscope which would allow the commander to observe in turret-down position.
Front view of a tank in turret-down and hull-down positions. A vehicle in a position with a background is more difficult to observe than one which is skylined.
A tank's exposed belly armour is vulnerable to even modest antitank weapons. This is a Panther tank , cresting a hill.
An M1 Abrams tank in hull down, turret down, and hidden positions behind a crest of ground. Shown to the left is the more exposed hull-down position a T-72 must adopt because of its main gun's limited range of depression (five degrees vs. the M1's ten degrees).
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