Go to Horon Village and take the east exit out. Go down, and right twice. Take to the blue Pirate and head to Subrosia to the Pirate's House (in the south-middle of the map). Go on the second floor and talk to the rightmost Pirate and learn the sequence he tells you: 33211444. Head back to the Pirate at the East Beach.

Talk to the Pirate and he'll leave. Now, do the sequence on the gate and go up when it opens. Go right twice to the Buried Pirate Ship (you saw the other half in Subrosia) and talk to the Pirate inside. Now, go to the northeastern-most point in the Desert to the Oasis. Behind the cracked wall are four fairies. Anyways, pick up the Red Skull and carry it around the Desert, stepping on the whirlpools until the Skull's mouth moves. If it does, go in the hole and get the Rusty Bell. Go back to the Pirate Ship and down the steps to enter Subrosia. Head to the Smithy and the Subrosians will make the Rusty Bell the Capn's Bell (make sure to use the choice "Do It!".

Head back to the Pirate's House and give them the Bell. A cinema will ensue with the Pirates setting sail and eventually getting Seasick and settling off the Western Coast, forming a bridge to the Explorer's Crypt, the seventh dungeon. From the Pirate Ship, go up and through the hosue to the Stump. Change the season to the Summer. Go back to the Ship and head right.

Climb up the vines and go up to enter Explorer's Crypt.