Sunless Sea: Zubmariner Edition

This can easily done from the start a new game.

Step 1: As soon as you start, choose "A Past Wreathed in Shadows" (It's way faster for this method).
Step 2: Press until you get to the Shipyard tab.
Step 3: Trade your ship for a Stymphalos-class Steam Launch
Step 4: Press to close the menu, then steer your ship into a wall, killing yourself instantly.
Step 5: Slip beneath the waves, choose your legacy, press accept. Rinse and repeat from step 1.