What is a one-sentence summary of the following article?
S. Tidal. To go home, make sure you have switched off the Birth Island code and enter the S.S. Tidal. It can be found in the south part of the island. You don't need a ticket to go home, but you will find yourself in Lilycove City, which is dangerous for trainers with low-level Pokémon. When you've completed all the steps and have a Deoxys, you want to make sure you save the game so you don't lose your progress.

Summary:
Board the S.  Save the game.