Pokemon eternal foam 3.0 Archie is on his way to the underwater cave. How can I find him?

1. Enter the game first. After the seventh hall, the sea will rise, as shown in the following figure:

2. Then surf to find a cave journey to the south, as shown below:

3. After entering the cave, an NPC will come forward to talk, as shown in the following figure:

4. After that, Archie will be found with them, as shown in the following figure: