A scout cruiser was a type of warship of the early 20th century, which were smaller, faster, more lightly armed and armoured than

protected cruiser Protected cruisers, a type of naval cruiser of the late-19th century, gained their description because an armoured deck offered protection for vital machine-spaces from fragments caused by shells exploding above them. Protected cruisers r ...

s or

light cruiser A light cruiser is a type of small or medium-sized warship. The term is a shortening of the phrase "light armored cruiser", describing a small ship that carried armor in the same way as an armored cruiser: a protective belt and deck. Prior to thi ...

s, but larger than contemporary destroyers. Intended for fleet scouting duties and acting as a

flotilla leader A flotilla leader was a warship of late 19th century and early 20th century navies suitable for commanding a flotilla of destroyers or other small warships, typically a small cruiser or a large destroyer (known as a destroyer leader). The flot ...

, a scout cruiser was typically armed with six to ten destroyer-type guns of 3-inch (76 mm) to 4.7-inch (120 mm) calibre, plus two to four

torpedo tube A torpedo tube is a cylindrical device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units (also referred to as torpedo launchers) installed abo ...

s. The British were the first to operate scout cruisers, when the

Royal Navy The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by Kingdom of England, English and Kingdom of Scotland, Scottish kings from the early medieval period, the first major maritime engagements were foug ...

acquired 15 ships divided into two distinct groups - the eight vessels all ordered under the 1903 Programme, and the seven later, heavier-armed vessels ordered under the 1907–1910 Programmes. All these ships served in

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...

, when the advent of better machinery and larger, faster destroyers and light cruisers had already made them obsolete. The other major operator of scout cruisers was the

Kingdom of Italy The Kingdom of Italy ( it, Regno d'Italia) was a state that existed from 1861, when Victor Emmanuel II of Sardinia was proclaimed King of Italy, until 1946, when civil discontent led to an institutional referendum to abandon the monarchy and ...

. With no conventional protected cruisers or light cruisers planned between 1900 and 1928, the Italian Royal Navy ( it, Regia Marina) instead operated a number of scout cruisers ('' esploratori'') from 1912 onwards. Ranging in size from enlarged destroyers to substantial, light cruiser-like ships, these ''esploratori'' were also given secondary capabilities as fast

minelayer A minelayer is any warship, submarine or military aircraft deploying explosive mines. Since World War I the term "minelayer" refers specifically to a naval ship used for deploying naval mines. "Mine planting" was the term for installing contro ...

s. Later ''esploratori'', such as the , carried extremely heavy armament for their modest size, capable of outgunning any destroyer of the early 1920s. However, by 1938 the surviving ''esploratori'' were re-rated as destroyers.

Scout cruiser designs

Austro-Hungarian Navy

* *

Brazilian Navy

Peruvian Navy

Regia Marina

''Note: this list includes all vessels rated as scouts (esploratori) by Italy.'' * – protected cruisers, rated as ''esploratori'' from 1914 to 1921 * * * ''Alessandro Poerio'' class - included * * * * - originally classified ''esploratori oceanici'' (ocean scouts), then re-rated light cruisers

Romanian Navy

Royal Navy

* * * * * * *

United States Navy

* – later re-classified as light cruisers (CL) * The first three ships were also designated "scout cruisers" (CS) when ordered, but in 1920, before any were launched, the Navy revised its classification system and they - and the ''Chester''s - became light cruisers (CL).