Don’t forget to create new Documents/SH4 folder once Dark Waters is activated.
Keep in mind DW is designed for 1920X1080 resolution (not tested on other resolution) and for the use of METRIC in realism settings (not tested on authentic/imperial)
In graphic settings, best Is to deactivate Post process filters, Full scene glare, Light shafts, Volumetric fog wich gives pretty bad Rendering results...
Last thing, in museum (quite long to load due to hundreds of units) you should avoid to load any submarine ... still some issues for them in museum
Good hunting!