Remember the Jeep carriers of WW 2? No hangars yet they operated Fairey Swordfish and Grumman Wildcats / Martlets off them? The USN were astonished when they saw them but British sailors were quite used to austerity conditions on their escort vessels.
In response to the massive shipping losses against German U-Boats in early WWII, Miles Aircraft propose a version of their M.38 Messenger for anti-submarine duty loaded with a couple of bombs/depth charges. Takeoff was was assisted by small disposable rockets and landing was on a 60' x 60' platform rigged on the back of a merchant ship with a net for backup:
Unlike this illustration from the NASM collection, the plan evolved after experiments on land to include an arrestor hook and wires and a net made of two vertical panels to catch the wings but open in the middle to let the prop go through. They even experimented with an M.18 trainer flying right into the net still in the air with no ill effects and landed an M.38 on aircraft carrier with no issues. It was never put into practice.