The below is a walkthrough on The Lost Galleon dungeon in Baldo The Guardian Owls!
After you complete A Hidden Path quest, crouch through the newly opened dark passage then head forward until you see a stone block on the right. Push it straight off the cliff then use the stairs to head down there. Continue straight ahead then crouch through another dark opening in the side of the ship. Once inside the ship, push the wooden box out of the way to reveal a set of stairs. Climb down to find a room with a cannon. Push the box blocking the cannon out of the way then push the cannon straight ahead to block the gate from dropping down. Open the chest to receive the Dungeon Key.
Head back up the stairs then go into the room blocked by a tentacle. To remove the tentacle, throw the nearby pumpkin at it. Proceed through the door to find a chest on the right. In this room head through the door on the left (across from the chest) to wind up outside. Use the pots to defeat the 2 tentacles then head through the door to reenter the ship. Once inside use the pots to destroy the 2 tentacles then go back to the chest to loot 10 Dindi.
Return to the main room with the stairs leading down then go through the door to the left of the pumpkin. Push the boxes out of the way then use the key on the door to unlock it. Once inside, again push the boxes out of the way then push the box onto the golden square on the floor to open the door. Push the box blocking the door then head outside. Use the pot to defeat the tentacle then proceed inside to reach a room with 2 swinging boxes. Work your way around this room, defeating the tentacles to reach the chest. Unlock it to receive the Dungeon Key.
Head back outside then pick up the pot. Carry it to the end of the walkway then throw it at the bell. This will lower the lifeboat. Be careful in the next room as there are 2 skeletons and 2 rats. Defeat the enemies in this room to unlock the chest that contains a Dungeon Key.
Unlock the door in this room then proceed through it to continue on. Head through the 1st door (door on the southwestern side of the room). Follow the path to reach a lever on the post. Push the lever until the chest lowers completely to the ground below. You’ll see a brief scene when it reaches the ground. Push the box out of the way then enter through the door to reach the room with the stairs leading down. Head down those stairs and enter through the door straight ahead to find the chest inside guarded by tentacles. Use the skulls laying around the edges of the room to defeat the blue tentacles. Once all have been destroyed, the red ones will disappear allowing you to open the chest that contains a Dungeon Key.
Backtrack up the stairs and into the room where you used the lever to reach the room with a cannon and 3 rooms. Push the cannon out of the way then head through the door it was previously blocking. There will be rats with 4 pressure points on the ground in this room. You’re going to have to avoid the rats as you need to place the pots on the pressure pads. You’ll notice that there are only 2 pots so you must not destroy them. Place them on 2 pressure points, the rat will stand on the one near the painting and you must stand on the last one. Once all 4 pressure points have weight on them, the door in this room will unbar.
Head through it and go through the door on the south side of the room. Push the cannon out of the way then return to the previous room. Push the cannon to crush the tentacle poking through the window. Head through the door previously blocked by the tentacle. In this room there will be 3 tentacles. Quickly run past them and go up the stairs to reach a locked door. Use a key to open it. In this room first defeat the 3 tentacles. Next, start on the right side of the room and push the box following the marks on the floor until it falls down where the tentacle was next to the guardian symbol. Use your Guardian’s Horn on the guardian symbol to unlock the door. On the left side of the room push the box to reveal stairs leading down. Climb down the stairs then push the box towards the wall with the water pouring out. Head down the stairs and run through the cannon fire and swinging boxes (without getting hit!!) then go through the next door. Defeat the 2 tentacles in this room using the pots then push the lever on the post to raise the chest. Keep going until a small scene showing the chest reaching the top plays.
Now your going to backtrack quite a ways to reach this chest. In fact, you’re going to want to go all the way back to where you first started on the ship. Once in the room containing the pumpkin and stairs leading down, head through the door to the left of the pumpkin (and diagonally from the stairs leading down). Open the chest now accessible in this room to receive the Owl Sword!
With your sword in hand, you can now do some cleanup! Head through the door on the far side of the room and use the sword to defeat the 2 tentacles covering the chest. Open the chest to receive 10 Dindi. Proceed through the door to reach the outside of the ship then use the lifeboat to climb into the window of the room where the skeletons were. Head through the previously locked door then go through the door on the right side after defeating the tentacle to reach a grid-like room with a bunch of cells and tentacles. Work your way through this area, defeating tentacles as you go, to reach the wooden elevator. Push the cannon out of the way then stand on it while holding a pot. Throw a pot at the lever to descend.
Press forward a short way then push the cannon to unblock the way. Before you head through the door, jump into the water and push the stacks of wooden crates to enable one to end up on the right side to complete the walkway leading to the chest.
Once you’ve correctly lined the walkway up, you’ll hear a reassuring sound of triumph! Open the chest to receive the Triangle Owl Key!
Head into the next room with all the cannon fire and take a right to head north past one firing cannon. Head up the stairs then the ladder to reach a familiar room with the guardian symbol. Before you head up the stairs, go through the door across from the symbol and defeat the tentacles to reach a chest containing 10 Dindi!
Go back through the door then up the stairs to reach the top deck of the ship. Defeat the tentacle immediately on the right then push the box out of the way. Next, push the owl statue behind the blue bell onto the pressure point to open the stairs on the north side of the deck. Instead of going that way, first go down to the south side of the deck and push the 2 cannons out of the way so you have access to the golden bell. Head to the north side of the boat with the captain’s wheel and clear all the tentacles. Just before the red door underneath the captain’s wheel, there is a pair of boxes. Move them to reveal stairs!
Climb on down into the dark room. Be wary of the 2 rats and walk up the stairs and read the note in front of the piano. Exit the room to return to the deck. Hit the bells in the following order: red, yellow and blue. The red door under the captain’s wheel will now open. Proceed through it to find a locked gate. Open it and head up the stairs. Push the box next to the bed to reveal stairs. Climb down then interact with the triangle under the octopus on the wall on the left side of the area. Follow the path forward, going across the makeshift bridge, until you reach the stairs leading down. Head on down to reach a water-filled room where a boss fight takes place. Defeat it then loot the chest to receive the Pru Po Key! Next, crouch through the small dark hole to the left of the chest to exit the ship. Hit the lever with your sword then grab the pumpkin and carry it to the wooden platform. While standing on the platform, throw the pumpkin at the lever to ascend.