I'm having trouble with this and I know others are too so it needs a thread. To begin with I think you need to be level 11 to even access this quest. You can then gather old pieces of cloth from bottles washed ashore in the beach area. Once you have collected old cloth A, B, and C being hem to Ratas and he'll make you an old map. He also hints that Damas has an old key for the pirate ship and whenyou talk to him about it he'll sell the key for around 5500 gold. Now that you have the map and key you can talk to Ratas again and follow the coordinates he gives you to walk on a hidden road in the ocean which led me to the west side of the ship you can see just off shore and... I'm stuck! I can't get in
Did I miss something? Hopefully someone can clear this ip and this thread can help others with this quest.
A couple things to add: once in (after tapping the water just outside the ship) you'll encounter a few other doors like that (with an invisible "npc" you need to tap to go through). The hallway door is opened by a key dropped by the "sweeper". Captain's Cabin door is opened by a key dropped by treasure chests.
Beyond that I'm not sure where to find keys for the other doors (there are two which are pretty close to each other, storage room and I forgot the other), I actually came here hoping for help on the issue. I'm guessing that keys to those doors are also dropped by treasure chests, I'll post again if I find anything.