To line up a carrier with the wind for take-offs and landings and hold it steady in a rough sea is a very difficult task. Linking multiple carriers under normal sea conditions for proper aircraft use may well be close to impossible.

I'm not really sure of the benefit of this. If carriers weren't long enough, we could just make them longer--even a supercarrier is only 2/3 as long as the biggest supertankers. But instead, we've designed planes especially for them and it works pretty well.

There are google-videos of c-130's landing on a carrier deck, but at a certain wingspan, it become a risk that the wing will hit the superstructure. And if you're not talking about big-planes, you're probably thinking about flying an fighters (an F-15 eg) from a carrier--it could never survive the abrupt landing.

As for hooking two 1000ft ships together to make a 2000 foot runway, 2000 foot is still only a third as long as most land runways. The amount of structure you're going to need to lock these ships into one would be astonishing, even if it wasn't strong enough for heavy seas.

Then you'd have to keep the whole length of it clear to land your ground-based plane--pretty hard to fight a battle with only one plane on deck at a time.

You may be interested in the Freedom Ship.

http://www.freedomship.com/