Kill all the Heartless here and the two will come out, revealing a save point. Save and go to the direction of the trident to reach the Undersea Valley. Here, you should see white clams and a red clam as you swim around.attack the WHITE clams for a Mega-Potion
, and Mega-Ether
. Hit the RED clam with Fire for a Mythril Shard
. Follow the tridents to the Undersea Cave.
Here, you should notice a hole with a white clam inside. Get in there and hit the clam for a Cottage. Head back out and swim up to the Undersea Gorge. In this area, dive and hit the white clam for a Mega-Ether
. Follow the tridents to Triton's Palace. Dive and hit the white clam for a Mega-Potion
. Hit the yellow clam with Thunder for a Mythril Shard
. Swim north towards Triton's Throne for a cut-scene. After the cut-scene, go back to the Throne. Here, dive and hit the white clam for a save point.
Leave the Palace. Ariel wants to show you something, so proceed to her Grotto. (the place where she's pointing to). When you regain control after the short dialogue, check the shelves for 2 treasure chests with a Torn Page
. Leave the room and there'll be a cut-scene with Ursula. Go back to the Undersea Valley and look for a dolphin. (If there's none, leave the screen and come back until it appears.) Rid the area of Heartless first, and grab onto the dolphin. It'll take you to a new area.
Here, dive and swim around the ocean floor for 2 chests with an Elixir
and a Mythril Shard
. Go inside the ship, and open the chest here for the Crystal Trident
. Swim to the back of stairs and into the hole that leads to the lower deck. You'll see a clam there, hit it to get a Mythril
. Leave the ship and go back to Ariel's Grotto. Here, approach the trident symbol. You'll see some long cut-scene. After that, head to Triton's Palace for another cut-scene. Go back to the Sunken Ship.
Once there, dive and swim towards the boulder with some carving on it. Examine it and Sebastian will move it for you. Go into the new area. Inside there's an intersection -- one path leads to the Cavern Nook and the other to Ursula's Lair. Take the path to the Cavern Nook. Here hit the smaller clam for a Mega-Ether
, then the larger clam for a save point. Save your game and proceed to Ursula's Lair. There will be a short cut-scene when you arrive, followed by a boss battle.
Boss Battle - Ursula
This battle is absolutely annoying. Not only will Ursula spin all over the place like there's no tomorrow, but her lackeys will also be there to bug you as well. So don't bother with close-range combat. Well... not until you stun her. Cast magic on her cauldron. If the liquid from the cauldron hits her, your screen will flash. This will not only damage her, but will also leave her stunned. Thus, giving you enough time to damage her further with your physical attacks.
After the battle, you'll get the Mermaid Kick ability. Equip it and go back to the Calm Depths. Press O repeatedly to swim against the current, towards a new cave labeled "???". Inside there will be a short cut-scene with Ursula. You'll have to fight her again after that.
Boss Battle - Ursula
She has grown awfully large this time around. But thankfully, she's a whole lot easier. Just swim to the back of her head and start smashing. When she says something like: "Now I'm angry!", that means she's about to use her mouth and suck you in. So use Mermaid Kick to get away. You can also use magic on her if you want to, but I suggest you reserve your MP for healing instead.
After a short dialogue between Triton and Sora, you'll get the Thundara
upgrade and the Ansem Report 3
. Go back to Ariel's Grotto for a cut-scene where Sora seals the keyhole. You'll receive the Crabclaw
key chain from Ariel afterwards. Find a save point and board your gummi ship.
There'll be a cut-scene with Ariel when you arrive, then Sebastian will teach you how to swim. (Press O rise and Square to dive.) When you regain control, just find and tag Flounder. Once done, there'll be another cut-scene where Sebastian and Flounder will hide inside the clam.