Although I regard myself as fairly knowledgeable on the subject, this video contained a surprisingly high number of details of the early evolution of aircraft carriers of which I was not aware.
Among some points I learned:
In WW1, the UK was planning an aerial torpedo attack on the High Seas Fleet that would have been bigger than that at Pearl Harbor (over 100 seaplane torpedo bombers - no fighters v. only 40 torpedo bombers at Pearl Harbor), but aircraft availability pushed off that plan until 1919.
The UK experimented with destroyer-towed barges for launching bomber aircraft.
UK carriers emitted a narrow beam radio signal rotating with a 1-minute period. Pilots could synchronize their watches with the time that the beam faced a given direction relative to the carrier. Thus, the time difference between signal received and time on the watch indicated the relative angle between the aircraft and the carrier. Multiple consecutive readings could establish the relative position and speed vector and allow the pilots to return. Without a synchronized watch, an enemy would have a more difficult time trying to use the signal to track the carrier.
Details of the pre-war RAF-RN rivalry.