Imagine a big boat, called a submarine, that can go underwater just like a dolphin. This submarine can go really deep underwater and has special machines to help it move and see in the darkness of the deep sea.
Now, imagine this submarine is also able to carry small planes, like the ones you see flying in the sky. But how can a submarine carry a plane? That's where the submarine aircraft carrier comes in!
A submarine aircraft carrier is a special submarine that has a secret dock inside, where planes can land and take off. The dock is like a big garage with a door that opens up to the surface of the water. When the submarine gets close to the surface, the door opens and the planes can fly out.
But why would anyone want to put planes in a submarine? Well, it's because submarines can move around secretly without being seen, even by other big boats. So, if the submarine is carrying planes, it can launch them and attack enemy ships or planes without being detected.
This type of submarine aircraft carrier is not very common, and only a few militaries in the world have one. But it's a very cool idea to imagine a big boat that can go both deep under the water and high up in the sky!