The Bubbly Basin DLC for Pokémon Pokopia packs in a lot of new aquatic content, and one of the more satisfying pieces is the Sharpedo Submarine building. Corphish wants one built in your underwater town, and the kit to make it is hiding in a spot most players walk right past. Here's exactly where to find it and how to get the structure built.
How to unlock Corphish first
Before you can find the Sharpedo Submarine Kit, you need Corphish living in your underwater community. To attract Corphish, build a Sandy Basin Tall Grass Habitat: place one Sandy Basin structure and surround it with four seabed tall grass pieces. You can pull up seagrass using Leafage, and there's a convenient spot for this right outside the tunnel leading to the Pokemon Center.
Once Corphish moves in, they'll flag you down with a request to build a Sharpedo-shaped submarine. That's your cue to go hunting.
Corphish habitat requirements
Where to find the Sharpedo Submarine Kit for free
The free kit is tucked inside the old Water Pokemon Gym on the east side of Bubbly Basin's main area. Getting there takes a few steps, but nothing here is difficult once you know the path.
Step-by-step route through the Water Gym
- Head to the east side of the main Bubbly Basin area and look for an orange rock wall.
- Use Rock Smash to break through it. You'll enter a room.
- Round the left corner to spot the entrance to the old Water Pokemon Gym.
- Go inside and break the sand blocks on the right side of the main room to access the hallway that leads up the stairs.
- At the top of the stairs, turn left immediately. A hallway runs ahead of you.
- Follow the hallway to a door at the far end. It opens into a bedroom with a staircase going down.
- At the bottom of those stairs, break through more sand blocks and head left.
- Squeeze through the gap at the bottom of the blocks. You'll come out in a poolroom.
- A Poke Ball sitting on the tiles holds the Submarine Kit.
Break the orange wall to enter
Can you buy the Submarine Kit instead?
Yes. If navigating the gym feels like more effort than it's worth right now, the PC Store near the Pokemon Center sells the Submarine Kit for 300 Life Coins once your environment reaches level 2. Select the kit from the store menu and choose the Purchase option to grab it immediately.
How to raise your environment level quickly
If you're not at level 2 yet and want to buy the kit, the fastest approach is to actively track down Pokemon traces across Bubbly Basin and build whatever habitats appear. Each habitat you complete and stock with the requested items pushes your environment level forward. The area around the Pokemon Center tunnel is a good starting point since multiple traces cluster there early on.
For a full rundown on constructing structures in Bubbly Basin, the Pokémon Pokopia building guide covers the core mechanics in detail.
How to build the Sharpedo Submarine
Once you have the kit, talk to Corphish. As a Build Pokemon, they're ready to get to work as soon as you hand it over.
What you need to build it
- 10x Iron Ore
- 5x Sea Glass Fragments
- 1x Corphish (Build Pokemon)
- Any 3x additional Pokemon
To place the structure, open your inventory with the X button, find the kit, and press A to set it down. One useful thing about building underwater in Bubbly Basin: you don't need to place structures on the ground. Floating blocks are automatically placed underneath to anchor the building wherever you position it in the water.
To add Pokemon to the project, ask each one to follow you, then interact with the build kit tray at the front of the structure. Select each Pokemon's picture under the Pokemon tab to confirm them. Once all materials and Pokemon are assigned, press Start Building. The construction takes one real-time hour to finish.
Need Iron Ore for the build? The Pokémon Pokopia lumber guide is worth checking alongside the material farming guides to keep your resource runs efficient.
What happens after the build is complete?
Once the hour is up, Corphish will be ready to move forward with their request. The Sharpedo Submarine counts as a decorative building for your underwater community, and completing it with Corphish advances their storyline in Bubbly Basin.
The Bubbly Basin DLC released on August 5, 2026, and it's packed with similar hidden items and habitat puzzles worth digging into. Check the full Pokémon Pokopia strategy guides collection for everything else the expansion has to offer.