Yeah, the Regulus cruise missiles were the size of fighters at the time. 32ft long, 21ft wingspan, 14,000lbs for the subsonic Regulus 1; 57ft long, 20ft wingspan, 23,000lbs for the supersonic Regulus 2.
The downside of those ideas was that the the submarine was stuck on the surface for 15-30 minutes readying the missiles (or planes) for launch.
In the early 2000s, when the Trident SSGNs were still in the planning stages, Lockheed proposed a drone that could be launched while the sub stayed underwater, the Cormorant link .
The LockMart Cormorant would float up to the surface and then fire a couple detachable rockets to get into the air. Then it would open up intakes and exhaust for a jet engine. It had the typical drone sensors (FLIR) and carried some weapons internally. After the mission, it would fly back out to sea, shut down the engine, and whip-stall to drop into the water. Then divers would fold the wings back up and attach the drone to the recovery rails in the missile tube.
Proposed loadout was 4x Cormorants, 4x tubes each with 3x navalized ATACMS (12x missiles), and about 14 tubes each with 7x Tomahawk missiles (98x missiles). Trident SSGNs have 20 or 22 tubes available for missiles (and drones), depending on what SEAL support gear they are carrying.
One junior officer proposed installing the 155mm Vertical Gun for Arsenal Ships (VGAS) into a couple tubes, as well. While the VGAS would require broaching the ship, the individual shells would be relatively cheap and quicker response than Tomahawks or the Cormorants. The downside of the VGAS, the long minimum range, isn't an issue for a sub. A sub could broach (be on the surface without blowing the ballast tanks), flop a couple hatches open, fire off a volley of 155mm shells, then purge the gun bore with nitrogen, shut hatches, and get off the surface in about 3 minutes. While it wasn't specified, there would probably be 2x or 4x VGAS tubes, replacing Tomahawk missiles.
That mix would be quite powerful. Shame that budget cuts killed the Cormorant program in 2008.
