The Spruance conversions to light aircraft carriers (Harrier style) are kinda neat, but I feel somewhat impractical....neat idea for a small navy to project some power, and for a large navy to diversify their combat power amongst some smaller ships, but, a small navy would be less than likely to be able to afford an air arm with Harriers, and a large navy would probably just buy a real aircraft carrier.
The submarine carrier at the end is....well....neat....but again, the practicality of it? Yikes. The low freeboard of a sub would mean that it's air operations would be effectively limited to nada unless it was dead calm. The Japanese in WWII built and ran a bunch of I-400's (I think) with float-planes. Neat concept, but not very effective in the long run.
Not to mention the difficulty in getting proper seals on those joints and hinges......I can see submariner's not wanting anything to do with that setup.
NS
