In this quest you are going to you are going to need some patience because collecting the map pieces may take some time.
Where to Start:
Start by going to Wingfril Island Beach and breaking Bottles, which can be found all alongside the coast. Inside you will either find nothing or a map piece. There are 3 pieces: Piece of Old Cloth A, Piece of Old Cloth B, and Piece of Old Cloth C (Piece of Old Cloth A is found only on Wingfril Island Beach, Piece of Old Cloth C is found only on the Island with the Lighthouse, and Piece of Old Cloth B is found on both).
At Level 11 or greater:
Once you have all the components for the Old Cloth Map, go to Rafril/Ratas and select the pirate ship chat option. He will then give you a Old Cloth Map that is Soulbound. Now that you have the Old Cloth Map, you need to buy the Rusty Key from Damas for 5,500 Gold. The Old Cloth Map may be discarded once the key is purchased. Once that is done here comes the hard part: getting there.
If you are from the Siras Empire it's easy because the path is right under the beach spawn. If you are from Lanos Kingdom you need to take the route just above Siras Airship (watch out for Knights). Once you get to the respective coordinates [492,1308] you can walk over the water (as shown in the video to the side) and follow a maze like path. Once you get to the end you must touch under Pirate Ship entrance and it will ask if you want to use the Rusty Key (it does not disappear after use). Use it and you will be inside the Pirate Ship. (Do not throw out key or else you will have to buy again.)
The Pirate Ship is divided into several different sections:
Pirate Ship Entrance
Pirate Ship 1F
The Hallway Door is located at (2050, 1010).
The Captain's Cabin Door is located at (731, 1522).
Pirate Ship 2F
The Warehouse Door is located at (2070, 1120).
The Storage Room is located at (2070, 1370).
This is where the Boss spawns: BOATSWAIN BRANKA (level 24).
Note: Many high levels farm this boss due to its short spawning intervals. Plan your visits accordingly.
Do not start this quest before you are ready because you must keep the Rusty Key in your inventory.