Lighthouse Seal

Walkthrough: After destroying the Stone Pillar Seal, head back to shore for a moment. Before moving forward with the remaining Seals, search for the underwater passage to where the ocean meets the cliff. There will be a treasure chest here, the same that will contain another Power moon. After nabbing it, head over to the Beak House Checkpoint. From there, you can obtain another Power Moon by shopping on the Yellow Dorrie. You grab more nearby Purple Coins behind the beach house.

From this point, you should be able to see the next Seal that lies near the Lighthouse in the distance. You can quickly cross to the lighthouse by using the flower on the edge of the beach that will boost Mario's speed, as well obtain another Power Moon by following the trail of musical notes. Once you reach the base of the lighthouse, you should notice it is surrounded by many spiked rocks that must be avoid. There will also be a small ledge on the lighthouse that will lead to more Purple Coins. On the other side of the lighthouse will be a local citizen, one that will inform you that you must use a nearby tunnel to enter the lighthouse. Quickly cross the sandbar to reach the tunnel, and then ground-pound to dive into the underwater section.

Once underwater, use Cappy to capture a nearby Cheep Cheep and then begin swimming. As you dodge other Cheep Cheep enemies, there will be another Power Moon within the alcove on a wall with three Cheep Cheep. Further along, Giant Eels will burst from large holes and try to attack when they do, forcing you to have to reach quickly in order to avoid them. Along the floor will be Purple Coins for the taking, so grab them before moving up and dodging more Eels straight into the next room. Quickly continue to the surface, leaving the Cheep Cheep behind so you can Warp Pipe to the top of the lighthouse. At the top, you will earn the next Power Moon that will break the second of the four seals, thus opening the next fountain. This will make the monster grow all the more angry.