I apologize for any confusion earlier. It seems like you are requesting a description for a modification that adds an atomic submarine to Minecraft Pocket Edition. Here is a possible description for such a mod:

The Atomic Submarine mod for Minecraft Pocket Edition allows players to explore the depths of the ocean in a fully functional submarine. This mod adds a new vehicle to the game that can be crafted and piloted by the player.

The submarine is equipped with a nuclear reactor that provides power and propels the vehicle through the water. It also includes a range of features such as periscope, sonar, and torpedoes that enable players to navigate, locate and defend against underwater dangers.

With this mod, players can explore new areas of the game that were previously inaccessible, such as deep-sea trenches, sunken ruins, and underwater caves. It provides a new dimension of gameplay that is both exciting and challenging.

Overall, the Atomic Submarine mod is an excellent addition to Minecraft Pocket Edition for players who love to explore and seek adventure.

Disclaimer :-
This is not an official Minecraft product. It is not approved by or associated with Mojang.