Depends on what you call simulation. Clicking on huge dials on ur screen or ... playing into a full 3D virtual world that simulate very good the u-boot era.
For example, I play with the UI hidden and shortcuts, so I have a nice and clean full screen. My favorite part is when I order dive, then go down in front of the obs. periscope and watch the depth dial waiting for a full dive. Then raise the scope and start hunting. Here is when the simulation start to break and that's because this game was not designed to be played on 100% realism.. stadimeter is broken, map tools too.. so is impossible to continue the full simulation.
But, is better than what we had in any previous SH where we played more like a Star Trek simulation than a real u-boot one. Teleport to stations, one click target tracking, ur scope was full with huge ugly dials etc. So I say the simulation part is working pretty much, with the help of few mod these bugs are solved.
What annoys me very much is the stupid AI. No matter if is the crew or the enemy, the AI is completely retarded and that's killing the game
