Amenities
HP/MP Spring, Revive Spring
While exploring the mostly empty Flooded World, you're likely to eventually come across the large land mass with the Temple of Water on it. You can't actually do anything here until you've explored the Wrecked Ship, however.
Once you return with Aria, examine the crystal shard. Now you can break the seal on the first floor of the Cave of Tides.
Once you return with Aria, examine the crystal shard. Now you can break the seal on the first floor of the Cave of Tides.