I read a post on another subreddit around the effectiveness of AA, which sounded dramatically worse than I imagined (using the Bismarck as an example) - what was the reality of the effectiveness of AA?
And conversely how effective were airborne attacks at bringing down ships? In some video games I play you can hit ships with dozens of bombs and 5-10 torpedos and still not sink them. Is that realistic?
How did both AA and airborne attacks on ships evolve over the course of the two world wars?
When it comes to the "bombs and torpedoes" question, the only real answer is "it depends." What kind of ship are we talking about? Is it at General Quarters, or is it December 7th, 1941? And what navy is the ship in?
A torpedo is, on the whole, better at sinking ships than bombs. Which makes sense if you think about it: bombs make holes on top of the ship, above the waterline. Torpedoes make holes under the waterline. Bombs let in air. Torpedoes let in water.
Both the Yamato and the Musashi required obscene numbers of torpedo hits before they sank. Musashi took up to 19 torpedoes before it sank, Yamato somewhere between 11 and 13; the difference being that most of them hit one side of the ship. Musashi's torpedo damage was split pretty evenly between both sides. Both took many bomb hits as well.
Now, those were the largest battleships ever built, but it does show that surviving ridiculous amounts of damage is possible. But on the flip side, it only took one bomb to destroy the USS Arizona.
Aircraft carriers were uniquely vulnerable to damage... all that aviation fuel and magazines full of torpedoes and bombs. Japanese submarine I-16 put three torpedoes into the side of USS Wasp while she was conducting flight operations. In less than an hour, the front half of the ship was an uncontrollable inferno. The Japanese carrier Akagi was hit by one bomb, also while conducting flight ops, and went up in flames as well.
Generally, the smaller the ship, the easier it was to kill. And aircraft were very good indeed at sinking ships.