Here is the full list of all 20 Ghost on the Shore achievements.
You found your true home
You've seen all visions
You arrived on Dark Rogue sailing your boat
Unlock the safe in Cordelia's study
You arrived on Little Rogue
Unlock the filing cabinet in the school
You arrived on The Rogue Islands
You arrived on Dark Rogue walking the tidal causeway
Collect all the tapes
Collect all the letters
Draw all the possible locations
Reach all endings
Sail away from The Rogues
Become the ghost on the shore
Find eternal love
Collect all journal entries
Find all contraband bottles
Ring the tavern bell
Try and sneak past Beatrice twice
Stand in an outhouse for at least 10 seconds