When talking about modern sub sim most people are trapped with the thoughts of DW and only DW or SC.
There are many types of simulation. There's study sim such as Falcon 4.0 and Blackshark. There's immersion sim such as IL-2 and SH3 and SH4.
Then there's functionality sim such as Sub Command and Dangerous Waters.
I wouldn't call DW an immersion sim because it's not the type of game where you get to experience being a captain of a modern sub. I wouldn't call DW a study sim either because it's too simple to be one however DW tries to simulate the functionality of the many different naval warfare platform in the forms of working stations. This is the core of DW.
There's yet to be an immersion sim of modern sub game.
