Here is the full list of all 28 Stranded Sails - there are Explorers of the Cursed Islands achievements.
Complete the Story Questline
Lift the Curse
Discover all Lore Artifacts
Discover all Items
Find and dig up all buried Golden Tools
Discover all cooking recipes
Discover the whole Map
Unlock all Hats by increasing your Crew's Happiness Level and mastering the Ancestor's Trial
Unlock all structures in your camp by increasing your Crew's Happiness Level and build them
Defeat 50 consecutive waves of hard difficulty enemies in the Ancestor's Trial
Discover all Spice Seeds
Unlock all tool upgrades by increasing your Crew's Happiness Level
Complete the Ship
Reach Crew Happiness Level 60
Defeat 70 consecutive waves of medium difficulty enemies in the Ancestor's Trial
Defeat 100 consecutive waves of easy difficulty enemies in the Ancestor's Trial
Discover every Fish
Summon the Ancestor
Complete your first combat encounter
Unlock all Tools
Reunite the whole Crew
Build all of the Crew member's shacks
Discover all Crop Seeds
Unlock the Stew for the Crew
Discover your first cooking recipe
Craft your first Item
Cook your first Food
Survive the shipwreck