Alright, DMC is in my posession so here you go:
There are a few introductory pages (6-7) about the ocean floor, reefs, tectonic plates, trenches, tides, and tidal waves.
Then there are supplemental ship and sea rules (10 pages) which cover ship speed, and ship modifications. Modifications include a ram, special sails, armor plating, etc. There are also a couple of pages which describe ship types (caravel, frigate, etc.). There's also a couple of pages of notes on underwater adventuing (swimming, breathing, etc.).
The next section is all about weather (30 pages). There are several tables (similar to AEG's Toolbox) which list the effects of weather based on the climate (arctic, tropical, etc.) and the time of day. It describes the condition and also lists the effect the weather has on skills. (For example, in rainy conditions, search and spot are affected.)
The next chapter (10 pages) contains new skills, feats, and prestige classes. I would reserve most of the feats here as for NPCs, as land-based PCs may find most of them of limited use. (For example, "Fast Swim" which is like the "Run" feat, but for swimming.) There are 4 prestige classes: Diver, Mariner, Navigator, and Songchanger. Only the songchanger seems to have a real benefit to land-based campaigns (YMMV and all that).
Then we have new magic items (11 pages), followed by new monsters (43 pages), and new spells (8 pages).
Adventures then follow, with the first (12 pages) being for 5th level characters. That is followed by one (18 pages) for 6-8th level characters. Finally, there is one for 9th level characters (22 pages).
The book then ends with two appendices: one an appendix of stat blocks of monsters and NPCs for the adventures, and the other has two tables: a "random shipboard event and monster encounter" table (d100), and an Aquatic Monster Encounters table (d1000).
So there you go.