Time to set sail! Well, there is one problem - you cannot set sail without a sail. The King of Red Lions, although he can speak, has no sail. This is why he brought you here - to find a sail, as well as some other items you may want for your upcoming adventure.
He is the man in the large blue jacket. Speak to him to hear his story and then get offered to buy THAT for 80 Rupees. What is THAT, you may ask? It is none other than a sail! Since you (hopefully) did what I requested early in the game, you shall be able to pay the price for the sail. Zunari has nothing else at the moment, however.
At this point, you could head back to the King of Red Lions - or do some sidequests, one of which you’ll have to do anyways. Continue along the dirt path until you reach the top of the staircase. Enter the building to the left to earn the ability to play a squid-shooting game.
It is pretty simple, almost like Battleship. Win the first time to earn a highly valuable Piece of Heart; two more wins earn you two Treasure Charts. Before you leave, check behind the ship in the background for three Yellow Rupees (10 Rupees each; 30 in all).
Inside, you’ll see a man in clothing like yours in a cell. The cell is locked, though. Smash the pots to the left of the entrance to see a switch. Step on it to unlock the cell. The green-clothed man, Tingle, will then thank you in a weird way with a Tingle Chart and a Tingle Turner (you’ll likely have to ignore the latter; you’re either playing this on a Wii or have a DS/DS Lite rather than a GBA).
He’ll then leave, leaving the cell open. Enter it (crawl under the bed for a Blue Rupee (5 Rupees)) then crawl into the hole. Use first-person view in the tunnel (push the C-Stick up). Whenever you come to an intersection, if you see wood on any path, DO NOT go along that path.
There is a rat there that will drop you from the wood platform into the sea - causing you to start this side-quest over. Eventually, you’ll come to a room with a chest inside. In the chest is a Picto Box, the Legend of Zelda version of the camera.
After grabbing the Picto Box, return to the King of Red Lions. He shall explain how to navigate at sea, use the Sea Chart, etc. I’ll give a summarized version of it:
- At sea, there will be a translucent yellow arrow behind the boat. This shows the wind direction in relevance to the way the boat is facing. For maximum speed, have the arrow pointing to the front of the boat.
- At sea, you can use the sail to travel with reliance on the wind, or without the sail. Without it, you'll need to use R to cruise.
- At sea, exit the boat by pressing A to remove the sail/other object. Hold A to stop. Then, once fully stopped, press A to exit the boat. You can then talk to the King of Red Lions or re-enter the boat with A.
- Finally, you will navigate via Sea Chart. The Sea Chart consists of a 7X7 square map.
Once you understand the above, the King of Red Lions also mentions that the winds are blowing east - towards your next destination. Set the sail to Y, X, or Z, then press that button while on the boat. Turn towards the east by using the Control Stick.
Your next destination may be Dragon Roost Island, two squares east of Windfall, but visit the island in-between the two - Pawprint Island.