Witcher 3 Pearls of the Coast Walkthrough
Start Location: on the small group of islands just to the south of Kaer Trolde Harbour on Ard Skellig. You can access them easily via any nearby boat, or alternatively taking the dirt path leading to the northwest from the town of Sund and swimming across to the islands at the closest possible point.
As you approach the abandoned encampment here, you’ll see that it is overrun by Deserters. There is a group of 5-6 of them an all at. Once you have cleared the area of the bad guys, loot their corpses. One of them will be holding an Unsent Letter.
Read the Unsent Letter in the Key Items section of the inventory. This will update our objectives. Make your way to the objective marker directly to the east of your current location.
Climb safely down the cliff until you can enter the water below to reach the yellow search area on the mini-map. Dive under the water and use your Witcher Senses to find a chest and a corpse nearby. Loot these for a new Steel Sword – Inis and some other goodies.
This will also end the side-quest.