Plunging fire

[1][2] In naval warfare, plunging shellfire was theoretically capable of penetrating an enemy ship's thinner deck armor rather than firing directly at a warship's heavily armored side.

Plunging fire in terrestrial warfare allows attacking a target not in direct line of sight, for example over the brow of a hill engaging in a reverse slope defence.

The Vickers machine gun was used for indirect fire against enemy positions at ranges up to 4,500 yd (4,115 m) with Mark VIIIz ammunition.

This plunging fire was used to great effect against specific features or points of interest that might be observed by a forward observer, or zeroed in at one time for future attacks, much to the surprise and confusion of the enemy.

The Australian Army still trains specialist infantry units, called Direct Fires Support Weapons DFSW teams, to perform an indirect sustained fire role with the MAG 58 GPMG, fitted with a C2A2 Support Weapons Sight[3][4] - similar to a mortar sight.