Joffre, Malta, and an Admiral-class carrier conversion

Which unbuilt carrier designs would have been worth completing?

Joffre and Malta are preferred completions. An Admiral-class carrier with a vast hangar and deck-edge lifts is a more speculative choice whose original design cannot be produced as proof.

Joffre would have shown where French carrier development was heading, while completing the Malta class could have simplified the Royal Navy's later carrier force. A more speculative choice is an Admiral-class hull converted by Cammell Laird. Alex Clarke believes references surrounding the idea imply that a design existed, but explicitly says he cannot produce the design as proof. The imagined carrier has one long hangar of Eagle-like height and deck-edge lifts, drawing on Cammell Laird's later advocacy during Ark Royal's development. That combination offers a very large hangar and a different starting point for British aircraft handling, conditional on the proposal and features being realized.