I'll extrapolate a little about 1950's submerged fleet... any comments are welcome..
First, let me recommend an excellent book "Attack from the sea" which is about development of Martin SeaMaster flying boat bomber and Convair SeaDart waterborne fighter...
http://www.amazon.com/Attack-Sea-Hi...bs_sr_1?ie=UTF8&s=books&qid=1220907333&sr=8-1
On submersible aircraft carriers, I think about the only time they can be considered to be worth trouble would be around early 1950's when cruise missiles were still unreliable, ballistic missiles still the future and the budget money was ample. Invention of nuclear weapons makes the point of aircraft carrying quite a little throw-weight quite moot. Alternatively one may consider the point that SAM's were still the future wave of technology and maybe not so reliable that one would rely on the air defenses for that.
So, let's go to ATL mode...
As a result of these extraordinary decisions the submerged aircraft carriers were born. The first submerged aircraft carrier was a conversion of a Guppy converted Balao-class submarine USS Tincan. As it's "air wing" it had a single FJ Fury fighter carrying a Mk 7 tactical nuclear bomb and a lot of extra fuel, giving this USN Sabre derivative a range of some 1000km's. The equipment for the pilot included an elaborate survival gear intended to keep the pilot alive after he had ejected close to the launching submarine. Naturally, a landing to a friendly base was the preferred option.
The FJ Fury was mounted in a container behind Tincan's sail. Inside the container was the most critical piece of equipment, ZELL launch rails for zero-length launches enabling the launching of a high performance jet from the submarine.
http://www.vectorsite.net/avzel.html
Compared to the cancelled (in this ATL) Regulus cruise missiles the FJ Fury offered much more credible way to deliver a nuclear warhead. After many publicity stunts the first operational patrol of USS Tincan was made in 1955.
The FJ Fury was just an interim aircraft before introduction of F2Y Sea Dart into operational service (enter handwavium) in 1957. Construction of new submerged aircraft carriers carrying six of these planes was given a very high priority, as Sea Darts were seen as a way of giving the United States a truly survivable retaliation capability. Initial ability, employing buddy refuelling, was clumsy but effective as SeaDarts were at their best in low altitudes. In war situation they would have delivered their B28 bombs deep into Soviet Union with deadly accuracy.
Later on it has been questioned whether these huge nuclear powered submarines were necessary as some have questioned that a good enough ballistic missile might have been produced to serve aboard the ships earlier than 1980's. Countercritics have pointed out that putting ballistic missiles aboard submarines would have posed tremendous security risks and might even have risked an accidental nuclear war due to irreversbile nature of taking a decision to employ nuclear weapons via ballistic delivery. Ballistic missile submarines would have also been essentially single-use items without any relevance to other tasks than massive nuclear conflagration.
Cold War would not have been Cold War without US-Soviet competition and British innovations. Soviets had considered also various cruise missile schemes but with US example made their own submerged aircraft carriers. First of them was almost exact copy of USS Tincan, a modified Zulu-class submarine employing a MiG-19 with ZELL-arrangement. These experimental craft were supplanted by operational ECHO-class (ATL) submerged aircraft carriers carrying Beriev-designed flying boat fighters.
With difference of US practice the mission of the Soviet submerged aircraft carriers was essentially defensive. They were to patrol in Soviet northern waters and also under the ice pack and surface irregularly deploying their fighters irregularly, making the task of SAC much harder in penetrating Soviet air defences. Additionally they were to support Soviet seaborne striking force based in similar concept to the abortive Martin SeaMaster Seaborne striking force. Although Beriev-10 flying boat (historical) had teething problems, it would prove to be a troublesome theoretical foe against US air defences.