The location with the scroll (a small ship that can randomly appear in one of the dead ends) is intended to have a very small chance of generating, which can sometimes result in it not appearing for over 50 playthroughs of the mission. To maximize your chances of finding the ship, please make sure to do the following:

1. Only search for it in the part before the drawbridge, and quit the mission if you do not find it there. While there is a chance it might appear after the drawbridge, it takes less time to look for it that way.

2. As soon as you enter the mission, open the map to check how many secrets are present. If you've already beaten Obsidian Pinnacle and used the button inside the Camp's church, then the mission will have 2 guaranteed secrets, meaning you should only search if there are 3 secrets shown or more. If you haven't used the church button yet, then there will be only 1 guaranteed secret, meaning you should search when there are 2 secrets shown or more.