True, you have to respect the threat of airpower and just stay out of range if it’s too much - usually early in the game.
To survive, a fleet needs both fodder and firepower.
For navies, the first “fodder” that adds stability to the defence is the free repairable hit of battleships ! Then transports or subs (depending whether attacker also can add surface ships: against air alone subs can be lost first; against air+navy subs are better than transports).
As said before, the best defensive firepower is from fighters (with the required number of carriers to land on), plus any existing battleships and destroyers (usually not worth building new, but surely using the existing ones!). Also, fighters of other powers can land on carriers (ex. UK carrier built round 1 + US fighters).
Joining different allies gives a great defender’s advantage (and defender’s only; each ally may be too weak to counterattack the German navy on its own, and it’s best to increase only one of them to prepare for the kill).
Typical survival scenarios:
NW of Africa before German round 2:
UK battleship, 2 transports, US destroyer, 2 trans, USSR sub
Holds reasonably against 4 fighters, 1 bomber. OK, may take losses but cheaper than German planes.
May deter even 5 fighters, 1 bomber if Germany doesn’t like air losses.
or
SW of Britain before German round 2 (UK build 2 transports)
UK battleship, 4 transports, US destroyer, 2 trans, USSR sub
Holds reasonably against 5 fighters, 1 bomber.