Here is the full list of all 14 Submerged: Hidden Depths achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Collect all Flowers
Collect all Creatures
Collect all Boat Boosts
Finish the Campaign
Collect all Styles
Collect all Diaries
Visit all Landmarks
Collect all Relics
Use all Lookouts
Change Body Style
View a Relic at the Home Base
Put a Flower in your hair
Change Boat Style
Change Hair Style