I really enjoyed this setting and approach to play. It's super evocative and makes the world feel very real. 

I'm super excited to see Sunk Cost develop!

I love submarines and have been waiting a long time for more games to use them. The fantasy-meets-industrialization theme is also super interesting. 

Inspired by the cities and factions in Cardinal Basin, I made a few smaller Blades in the Dark-style factions for it.

https://www.explorersdesign.com/factions-sunk-cost/

First off: “Sunk Cost”? Great name, very evocative, horrific SEO.

Secondly: Freebooter is the best kind of mariner.

Third: Genuinely, and maybe this is an unpopular opinion, the character incentive for taking big risks is obviously the chance of a big reward. Therefore I want the party phase to have more weight than anything else. Make of that what you will.