You can avoid AP Bombs, just like you can avoid being deleted by a BB. But guess what? Those aren't always guaranteed to prevent you form being deleted by a BB just like turning towards, trying to stick near AA cruisers and changing speed won't always save you from a CV's planes but they can sure how minimize the damage you may attack. If not? Oh well, it can be frustrating to suddenly lose all of your hp because of one simple thing but its apart of the game. Just move on and play another ship.