CFS3 is a DX7 title, not 8, and the water reflects that. It's the old style "moving textures to simulate water" type. It's an old engine that was updated for the latest versions of MSFS but the CFS series was cancelled so it never got them. As a result, CFS3 has always lagged behind Il-2, LOMAC, and others in the graphical department. Even the TK sims at release were superior, although the terrain detail is much better in the bigger-budgeted CFS3 as far as cities and things and units moving around on the ground go.
It definitely feels dated in many ways when you play it, but if you can see past it there is fun to be had. There are also more WWII planes you can fly there that you can't anywhere else. There are a lot of older WWII birds for the TK sims, but most are out of sync with current patches. Il-2 has a lot of flyable planes, but there are many that are either nonflyable (at least before the modding started) or nonexistent. CFS3 let you DL them from avhistory or other sites and fly and fight in them all day.