The Merchant Ship Fighter Unit (MSFU) was a Royal Air Force operational aircraft unit based at RAF Speke, in south Liverpool, {{now Liverpool John Lennon Airport]] during World War II.  The role of the MSFU was to provide pilots, crews, support personnel and aircraft to operate from 35 merchant ships outfitted with a catapult on the bow, referred to as Catapult Aircraft Merchant ships (CAM ships), a stop-gap initiative to provide air support to convoys out of reach of land in the early part of the war when aircraft carriers were scarce.

Fulmars were also deployed as CAM fighters


Hawker Hurricane XII ‘P3700 / RF-E’ (G-HURI) by Alan Wilson

Via Flickr:

c/n 72036.
Although in an authentic Battle of Britain colour scheme, this is actually a Canadian built Hurricane which saw RCAF service as ‘5711’.
It is operated by the Historic Aircraft Collection and is seen during winter maintenance in Hangar 3 at the Imperial War Museum, Duxford Airfield, Cambridgeshire, UK.