Naval AA Immune nav.

At 45 agility, naval vessels cannot attack you with their AA guns outside of kamikaze missions. Period. Air defense plays no role in naval air raids, air attack is also pointless. Enemy AA is only effective at reducing your attack number but you can't combat this in any way. If the enemy has pesky carriers you'll need self sealing fuel tanks to achieve adequate survivability against interceptors, but you will need 1 agility from your mio to remain immune to naval AA. - A cheap torpedo destroyer, or torpedo heavy cruiser counters carrier aircraft cheaply if your naval bombers land hits on enemy screens. Can't have carrier aircraft if you can't have carriers. - B non british enemy carriers won't launch sorties at night, except with one very specific doctrine milestone they won't get because you killed them first. At about ~10% agility from MIO, you can replace reduced strategic materials usage entirely with self sealing fuel tanks, and cut losses to enemy naval fighters down about tenfold. At 15%, an anti-ship missile becomes a real option while remaining utterly retaliation proof. Higher attack nav bombers sink fleets faster yes, but invincibility against non-interceptors is a hell of a drug. A cheap, almost zero resources aircraft that indefinitely causes enemy surface losses fundamentally forces your opponent to make unsustainable investments to maintain naval operations. This is how you can win the naval war by doing almost nothing.