How do you get to moss deep city blocked Pokemon emerald?

To reach Mossdeep City in Pokémon Emerald, you need to first defeat the Gym Leaders in Fortree City and then obtain the HM Surf. Afterward, head to Route 127 and use Surf to navigate through the water routes. You’ll eventually arrive at Mossdeep City, where you can challenge the local Gym Leaders, Tate and Liza. Make sure to explore the area and interact with the various NPCs for additional tips and items.