What the Royal Navy learned and missed in interwar exercises

Which pre-World War II Royal Navy exercises taught the most, and what useful lessons did they miss?

The big Mediterranean fleet exercises were most valuable, but exercise incentives distorted air targeting and understated how submarines could relocate after contact was lost.

The most valuable exercises brought the Home and Mediterranean Fleets together for large opposed manoeuvres. Their artificial incentives encouraged aircraft to attack prestigious carriers and capital ships. Under wartime fire, attacking an exposed destroyer at the edge of a formation could offer a better chance of survival. Henderson began questioning the exercise pattern around 1934-35, leaving limited time to change the equipment available. Anti-submarine preparation supported convoy organization and mass escort construction, but exercise rules did not adequately allow for a submarine moving after contact was lost. Improvements were still needed in the final attack, including carrying more depth charges. Existing ships had enough room to absorb those changes.