Have you bought Sunless Sea: Zumbariner Edition on the PS4, or purchased the Zubmariner add-on for the PC version, but aren’t sure how to get the Zumbarine? Here’s how.
As noted in the Zubmariner guide, head south from Fallen London till you hit the south coast, then east till you reach Port Carnelian. Dock there.
Visit the Fierce Philanthropist and convince her, by choosing the obviously appropriate options, that you’re interested in zumbarine travel.
Then, still at the port, visit the Hidden Workshop which is now unlocked. You need to increase your Experimental Modifications to 100. The quickest way to do this by choosing the second “Phase 1” option, four times, at a cost of 75 echoes each time.
Then, choose Phase 2. You’ll be prompted to get the Zonar blueprints.
Leave Port Carnelian and find (to the North West) Khan’s Shadow or Station 3.
If you find Station 3, search Shed Twelve to get the blueprints. If you make to Khan’s Shadow, search the wreck of the Stone Turtle to get the blueprints:
NOTE: It’s possible that the blueprints may be absent from one of these two locations. If so, go to the other.
Finally, return to Port Carnelian and to the Hidden Workshop to complete your zubmarine conversion which will let you, and all future captains, transform your ship into a zumbarine.