Fly-class gunboat

The Fly-class river gunboats (or small China gunboats ), collectively often referred to as the "Tigris gunboat flotilla", were a class of small but well-armed Royal Navy vessels designed specifically to patrol the Tigris river during the World War I Mesopotamian Campaign.

Design
They were fitted with one triple expansion steam engine driving one propeller housed in a tunnel to facilitate a very shallow draught.

Deployment
The vessels were built at Scotstoun, Glasgow in 1915 and 1916 and shipped out to Abadan in sections where they were assembled.

Firefly was captured by the Ottomans but recaptured at the Battle of Nahr-al-Kalek in February 1917. They served with the Royal Navy patrolling the Tigris River until being transferred to the Army during 1918. They were sold off beginning 1923.

The vessels
These vessels had the prefix "HM Gunboat"
 * Blackfly
 * Butterfly
 * Caddisfly
 * Cranefly
 * Dragonfly
 * Firefly
 * Gadfly
 * Grayfly
 * Greenfly
 * Hoverfly
 * Mayfly
 * Sawfly
 * Sedgefly
 * Snakefly
 * Stonefly
 * Waterfly