The Air Service objected that a distant target reduced the time its bombers could spend over the ship. That complaint exposed a geographical limit in Mitchell's coastal-defense proposal. Battleships could move along the coast, while a bomber force depended on the reach of its airfield. Covering different stretches of coastline could require several bases with the infrastructure to support large bomber forces. An enemy attacking beyond the chosen field's reach would leave the local aircraft unable to respond.
Notable Point · 1:44:47-1:45:36
Fixed airfields and mobile battleships cover different areas
Multiple airfields and supporting infrastructure complicate the cost and coverage of a bomber-based coastal defense.