I have both
1E and
2E D.G.U.T.S. now and am starting to compare them side-by-side. Not too much difference between the editions.
1E is by Guidon Games and has a black ship on a dark blue cover.
2E is by TSR and has a black ship with white sails on a light blue cover. The diagram is essentially the same, except for sail color.
Both editions have identical Forward introductions, except that they are dated differently. (I guess Gary had the same things to say in each year.)
1E has photographs of actual miniatures in play. These do not exist in
2E.
2E has some diagrams of a couple seabattles and where the ships were located. The ship locations are almost like tiny dots on the diagrams and are hard to read, in my opinion. These diagrams aren't in
1E.
Both editions contain a few illustrations of ship profiles, the same ones in each. The main tables and rules appear to be the same. Overall organization and table of contents are remarkably similar.
2E has a few extra pages of fleet action rules.
Otherwise, it looks mostly like a difference in font size.
