688i (Jane's) is the grandfather of DW. What's on the disk is what you get but its still a great way to learn the basics. No mods to worry about, I don't recall
ever seeing mods, but what you get is fairly stout.
There are some features in 688i that were dropped on later versions of the basic game (3d control room, port load outs, your friendly squadron commander
) and the 3D tends to be a little clunky (this was back in the Win95 days and I started calling the 688 3D model the "USS DuKey"). But I started playing 688i a couple of years after I left the Navy and I was impressed.
Sonalysts got a lot of the basics right and the canned missions and campaign were well designed and thought out (the campaign was based on a post-cold-war world and felt pretty accurate).
Sub Command and Dangerous Waters came out later on, but its uncanny how true those games stayed to 688i.