Full list of all 54 Sunless Sea achievements.
The base game contains 30 achievements, and there is 1 DLC pack containing 24 achievements.
Take the Shipmate legacy
Suffer Stone's Curse
Acquire the Eschatologue-class Dreadnaught
Discover The Dawn Machine
Achieve Antiquarian 10
Take the Pupil legacy
Create an ironclad will
Die 5 times in an unbroken lineage
Suffer Salt's Curse
Take the Rival legacy
Let your terror reach 100
Spend one year out at zee in an unbroken lineage
Download new stories
Recruit the imaginary officer
Visit the Surface
Achieve Admiralty's Favour 10
Take the Salvager legacy
Die for the first time
Let your terror reach 90
See Hunter's Keep burn
Woo a sweetheart in London
Die 10 times in an unbroken lineage
Send your child to zee
Spend five years out at zee in an unbroken lineage
Spend ten years out at zee in an unbroken lineage
Discover 'The Eye'
Suffer Storm's Curse
Take the Correspondent legacy
Complete the game without saving manually
Complete the game without ever choosing a past
Avoid being killed by the Unexploded Unclear Bomb
Perform an abyssal ritual to encounter Lady Black
Come face to face with the Constant Companion
Discover Undercrow
Accept a power of the deep zee
Escape underwater combat by resurfacing
Discover Aigul
Discover Anthe
Discover Dahut
Discover The Gant Pole
Discover Hideaway
Discover Low Barnet
Discover Nook
Discover Rosegate
Discover Scrimshander
Discover Wrack
Use an oasis to increase your oxygen levels
Use underwater currents to bear you on your way
Venture beneath the waves
Die of suffocation
Be killed by an underwater creature
Be killed by the Constant Companion
Complete the Zubmariner ambition
Collect all of Drownie Love-song, Drownie Counterpoint and Drownie Hymn