Creating a new tag, SOLNOR, for a new campaign setting noodling project. I previously did this with ODD D&D, a setting noodling project that I'd like to add a few more details to still, and maybe even run someday. By setting noodling, I don't mean to imply that I'm actually developing a setting that'll be ready to use. Rather, I'm developing a high concept, kicking it around a bit, maybe discussing a few implications of it, and then setting it loose. By that standard, ODD D&D could be considered complete, although--like I said, I'd like to do a bit more with it before I release it back into the wild. This setting will be more or less the same.
Solnor refers to the really big ocean in the world of Greyhawk. You could consider the setting to take place on Greyhawk if you wish (although there's no inherent reason why you need to). Rather, I just borrowed the name because I needed one quick and dirty.
There was a guy who used to post at ENWorld who always made gratuitous references to his setting, his game, and his hobbies, which seemed to be incredibly nautical. He had big tanks of fish. His setting, nominally Greyhawk, was completely "Under the Sea"--and yes, we sometimes made fun of him a bit by referring to his Little Mermaid setting. But mostly that's because he had a bad habit of name-dropping it all of the time, not because it wasn't actually a pretty cool idea.
So, that's where I'm going with this particular setting. An undersea setting. All PCs must choose races that are aquatic (or at least amphibious) since there is no expectation that a campaign set here will ever actually be on land.
Anyway, more to come as I noodle with it. Right now, all I've got is the high concept, and that's not enough to really do more than roll up your sleeves and get to work.