You remember Pinnacle's announcement of the Hostile Climes d20 series, right? Well known writers doing cool settings that can be used with nearly any campaign... this ringing a bell yet? The environment will play a major role in each book -- ah, now you remember. Well, it's here. The first book in the series is Depths of Despair by Matt Forbeck, which dives into "a city at the bottom of a mammoth whirlpool." Lots of aquatic humanoids at war with each other, complimented by "rules for boats, underwater travel and combat, new skills, feats, classes, prestige classes, weapons, equipment, and monsters" (basically, everything d20 fanatics look for). The 128 -page setting goes for a mere $20. Buy me one. And yourself, if you like.