Surf is perhaps one of the most important hidden moves you get in Pokemon Brilliant Diamond and Shining Pearl. This practical stealth move is necessary for traveling across oceans and bypassing certain areas such as lakes. You can't really beat the game without it. Fortunately, it is easy to obtain. Here's where to stand in the way of this important TM.
During the game, you will meet an NPC named Cynthia. She will help you in certain situations. Once you reach Pastoria City and defeat the Gym Leader there, Cynthia will appear and give you the medicine you need to help the Psyducks on Route 10. She will appear again when after healing them to ask you to bring the Ancient Spell to her grandmother in Heavenly City .
After a long drive through Route 10, you will meet Cynthia's grandmother. She will inform you that there is a "space man" in front of the ruins. Defeat the man and Grandma will tell you to search the ruins. Upon entering, Grandma will come in and give you the SurfTM. However, you won't be able to use it yet. First, you'll need to reach Hearthome City and defeat the Gym Leader. Once that's done, you'll be well on your way to navigating the open ocean.
