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