One of the things that I find interesting in the Pacific War is how tough American ships had become by the end of the war- not just the ships, but more importantly the crews' ability to deal with major damage. Look at the first year of the war, the kind of damage that put down the Lexington, the Northampton, etc. - and then compare it to late war incidents like the Franklin. A much newer ship, for sure, but that kind of damage would have been fatal a few years earlier.
Interestingly, old ships became much tougher as the war went on- not just thanks to modifications, but the crew. The torpedo that crippled the battleship Pennsylvania late in the war nearly sank her, but the crew managed to fight to keep her afloat and get her home. It's interesting to wonder if she'd have survived a hit like that in mid-1942. The ship itself hadn't changed all that much in terms of protection- but the damage control skills of the crew certainly had.
Something to consider: In 1942, the Lexington, Yorktown, Wasp, and Hornet were all lost, with Saratoga and Enterprise surviving (and both being beat up a few times that year). By the end of the war, the only other American aircraft carrier lost from the blue-water navy was the Princeton (I'm excluding CVEs since they were basically merchant hulls with flat tops). That's it. As the war progressed, the kamikaze became a factor, and Japan became more and more desperate in their attacks, the only carrier to actually sink was Princeton. Many were hit, some crippled, but none actually lost. No American battleship was lost following Pearl Harbor, despite a few that suffered major damage (Pennsylvania, North Carolina, etc.) It's quite the feat, really- hurting an American ship was one thing, but actually sinking it had become all but impossible.
