This is a project I started in Unreal Engine 4 a while back, got fed up with, dropped for a few months, and finally came back to. The project began in a Discord channel of a role-playing group for a game called From the Depths. FtD had some good ideas, but it's clunky, unrealistic, and not very well balanced. Our group in particular found it unsuitable for the early 20th-century-style naval battles we wanted to simulate. This is my attempt to do better. Needless to say this is pre-pre-pre-alpha footage and there's a lot to be done before it's ready for public consumption, but I'm quite proud of what I have so far.

[video=youtube]

The major difference of this game versus every other 3D ship construction game I can think of is that it scraps the voxel system for what I'm calling a "surface" system, because it works by placing flat surfaces whose endpoints are on a grid. This has a few advantages that made it ideal for the kind of game I want to make:

• Less performance drop with large constructions (a few large plates vs. thousands of small blocks in a voxel system)
  
• More room for player creativity as you're not limited to a finite palette of blocks
  
• Lends itself to realistic physics and damage models
  

Also, since the video went up I improved the texture mapping on the meshes and added a preview of the surface you're currently placing to the UI:

Here are some references I used for the math:
Per-triangle buoyancy that doesn't rely on knowing the volume
Equations to generate realistic waves
Implementation of the above in an Unreal Engine 4 shader