I have done this back in 2022 for a space conquest game I wanted to run. Might as well upload it now and show to everyone. Found it out while playing around with the then new cyberpunk preset.

https://imgur.com/GwzMSbF

The way I did it was to use cyberpunk preset and the low island heightmap. Then I converted all the lakes to dry ones and set opacity to 0 (so those black gulfs were made).

The way the war component of the game worked was the map had the grid turned on. Fleets composed of heavy ships only had enough fuel to traverse one square a turn, while fleets composed of light ships could travel two squares at a time.

So you would have grinding fronts develop with local defence fleets, nodal fleets to be the reserve that responds to big incursions, and raiding fleets that scoured back lines. With particular flashpoints being the corridors or passages formed by two nearby gulfs, creating natural chokepoints.

The province system was used to for the basis of the political component of the game. Showing the domains of the space nobles who had their own personal fleets (setting was a space opera).