The Great Lakes Cavern has a lot of water in it, and you'll be doing a lot of swimming. When you first enter the cave and swim/walk to the back wall, you'll come across a waterfall. There appears to be a spot with air bubbles where you can dive under the water, but you cant do it just yet. Instead go to the left down the dead end until you pick up the Air Herb, which will allow you to breath underwater. Return back to the waterfall and now you should be able to dive under the water.

You'll emerge just east of the exit, but on the other side of the rocky wall. There will be several places throughout the cave that you can dive into. You just have to keep an eye out for air bubbles rising to the surface. Not all air bubbles indicate passageways though. In this area there will be air bubbles coming up from the water, but they're actually monsters that are getting ready to surface and leap out of the water. Watch out for these air bubbles and try to swim away to avoid them. East from where you emerged you'll find another waterfall. Swim down it.

You'll land in a pool at the bottom of the waterfall. There will be a corridor leading to the east. Walk down the corridor and go up the staircase

In the next room, walk to the north. There will be a ramp to the northwest and a staircase to the northeast. The ramp leads you to the same waterfall you just jumped down, so you may not want to go that way unless you like walking in circles. Instead take the northeast staircase.

When you enter the next area, you're on a ledge next to a large pool of water. Ark will notice off to the distance a mysterious shadow under the water. Then a voice is heard calling for help! The shadow moves off to the south. Instead of following the shadow, swim along the western wall.

While swimming along the western wall you'll come to a spot where you have to swim down another waterfall. Go down it, but lean toward the left side. You'll land on a platform and get the Magic Anchor. The Anchor will make sure you don't get pulled downstream when you swim across a waterfall that you'll come to later on. Continue down the waterfall until you reach the bottom. When you land in the pool, take the path to the left.

There are two ways to go now. You can either dive underwater and go through that way, or you can take the doorway directly to the north. The doorway to the north will eventually lead you back to the room where you saw the shadow under water, but above the doorway that you originally entered the room with. From on the top ledge you can swim over to the right side and pick up 753 gems, fall back down the waterfall, and circle back until you get back to this room. The correct way to continue through the cave is to jump into the water and dive. When you surface, head for the exit to the north.

• Treasure
  • 753 Gems

The next thing you'll come across when entering the next are is a split in the corridor. There is a path to the right and a path to the left. The right-hand path leads to a dead end, so you would want to take the left path instead. Follow the left corridor and go up the stairs.

This area is filled with giant frogs. They can leap at you very fast and spit out orbs that when hit, will propel you against the opposite wall. They also spit out clouds of red poisonous gas, which are only curable with a Serum. A PCure wont work against poison this powerful. The way into the next area is in the northwest corner of this room. Go through the corridor, up the ramp, collect the treasure, and then leave.

• Treasure
  • GeoStaff

Follow the corridor to the east and you'll come across a trickle of water coming out of the wall. Use one of the rocks that are lying on the ground and throw it at the wall to release the water. Or if you run out of rocks, jump against the wall and fall down the hole. The wall that was preventing the water from falling will break and a waterfall will be here in it's place.

You'll fall back to the room that had the GeoStaff, but now it's filled with water. Swim back down the corridor until you come to the room that use to have the frogs in it. On one of the newly formed islands there will be a MagiRock. Also there is now a path you can reach in the northeast corner of the room.

• Treasure
  • MagiRock

Go down the ramp and then continue east. You'll come across a doorway. Go through the door and in the next area follow the path and go down the staircase.

You'll now come to a room with a large waterfall. You'll also see a staircase leading down directly south of your entrance, but that leads to the bottom of the waterfall and nothing more. Make sure you have the Magic Anchor equipped so you don't get swept down the waterfall, and swim to the opposite side. Climb out of the water and follow the path south.

The path leads south down some steps. When you reach the bottom, head to the east and you'll come across another waterfall. There is an outcrop of land that is closer to the waterfall then the rest of it. You have to swim under the waterfall from that outcrop. When you emerge from under the waterfall you'll be in a small room with a doorway.

Go through the doorway and you'll come across two water paths; you can swim to the west or swim to the east. It doesn't matter which path you take, they both end up at the top of the same waterfall. Swim down the waterfall.

There's a giant water dragon in front of you! The dragon doesn't seem to attack you, but the three starfish will. Two of them will just merely jump out of the water and onto the log that you're standing on. They are easy to hit when they land on the log.

The last remaining star is more difficult to destroy. It will pop out of the water, hover above you, and then try to drop onto the top of your head. If he misses, you have a split second to hit him before he jumps back into the water. If he does land on your head, he'll stick there. But the water dragon will spew flames from it's mouths and fry the starfish off of your head.

Once the three starfish are destroyed, the water dragon Gossie will want to help you. He'll give you the WaterPin and he'll lead you to Will. Will says he crashed his plane into the Great Lakes and was attacked by the starfish. Gossie protected him though.

Return back to Nirlake and talk to Will in his shop. He says that he would like to build a new plane, but a company called Lon Trade in Yonkou has started buying up all the scrap metal and raising the prices of the remaining metal. Leave Nirlake and leave the port of Freedom, sail past Liotto, turn west when you reach the end of the continent, and sail northwest until you reach a series of islands. A few of the islands have ports where you can land your ship. On one of the islands, there is a treasure chest that contains the Speed Shoes. You'll need them for YunKou.

• Treasure
  • Speed Shoes
  • 378 gems
  • Luck Potion
  • 1403 gems
  • Enbu Pike