That's right,OneShot.
Dangerous Waters has also got some graphic benefits besides (more beautyfull sea water,for example).On the other side,system requirements are a bit higher than ones of Sub Command (for example,I am getting lower FPS on my notebook while playing DW,comparing with those I get on Sub Command).
However,I think that only more experienced players will feel the actual differences between Sub Command and Dangerous Waters.Both sims are really very serious and sophisticated,so it takes a quite reasonable time to learn how to play them.
