Editing River monitor (section)

{{Short description|Military warship designed to patrol rivers}}
{{About-distinguish|the military boat type|Water monitor}}
{{Use dmy dates|date=July 2022}}

[[File:Monitor model2.jpg|thumb|upright=1.4|Model of USS ''Monitor'']]
'''River monitors''' are military craft designed to patrol rivers.
They are normally the largest of all riverine [[warships]] in river flotillas, and mount the heaviest weapons. The name originated from the US Navy's {{USS|Monitor}}, which made her first appearance in the [[American Civil War]], and being distinguished by the use of revolving [[gun turret]]s, which were particularly useful in rivers, whose narrow channels could severely limit the directions vessels could face.

River monitors were used on [[inland waterway]]s such as rivers, estuaries, deltas and lakes. Usually they had a shallow [[Draft (hull)|draft]] which was necessary for them to be able to operate in enclosed waters; but their displacement, size and draft varied depending on where they were used.

Most river monitors were lightly armored although this varied, with some carrying more armor. Exceptional examples, however, most notably the [[Royal Navy]]'s {{sclass|Lord Clive|monitor||warship}}s, which could operate in coastal or certain riparian/estuarine situations, bore extra-thick armor plating and heavy shore-bombardment guns, up to a massive 18 inches (457&nbsp;mm) in size. Typically, however, river monitors displayed a mixture of gun sizes from 3-inch (75&nbsp;mm) to 6-inch (152&nbsp;mm), plus [[machine gun]]s. This type of vessel overlaps with the [[river gunboat]] that would be armed with relatively small caliber cannons, or a mix of cannons and machine guns.