This is an interesting thread.
For me, immersion is key to enjoying a game. The goal of the graphic environment then is to aid immersion. And this is what is interesting, SH4 has a better sea than SH3...I agree....but SH3's sea immerses me more than SH4's. So I suppose its not just about sea texture, or transparency, or reflectivity, or sea state....its the result of all these things put together.
So for me, SH3 produces a better result, and hence imersion, even if some components of that result are better in SH4.
Am i making sense