(Redux) Basic Setting Info

You've learned a fair few things about the world.

[ABOVEWATER]

Not much is above water these days. There's just 16 Pillars -- massive, isolated island-cities built on and around structures that jut from the waves. And possibly the summits of some tall mountains, though nobody knows for sure.
It doesn't matter much, though, because...

---

[UNDERWATER]

You haven't been above the surface for three years (and several months, but who's counting). Drowning doesn't kill a body, as it turns out-- all it does is alter, like a particularly indiscriminate tailor. It becomes normal to breathe water (though talking remains difficult), to not eat or drink, to hardly age-- though death is rampant, despite rapid healing. Most conspicuously, you lose buoyancy. There's no swimming back up.
Subtler effects are still under study. Common folklore is more blunt: "if you weren't weird before, you're weird now."

-

BLOOD - Reacts with saltwater, producing a gooey pink substance. Also contains the totality of your* being. Lose enough blood and while cognition may be perfect, there's nobody behind the eyes. Injecting saltwater directly into the bloodstream causes a sort of "high", you've heard, but you tend to stay away from the sort of dregs of society that do that.
*Well, not -your- being. Richard's assured you that he's dealt with it. The totality of /your/ being is in your head, where it really ought to be, in your sincere opinion.

REALITY - Is a lot more flexible than you'd gotten used to. You've made a business of ignoring Richard's tangents on "laws" and such forth, but the gist of it seems to be that seawater is a lot more accommodating than harsh air and soil. If something is thought about hard enough, and in the correct manner, it can be realized. But the result generally only exists as long as it's being perceived, and even then has a habit of shifting in disconcerting ways.
Comes in four kinds: normal, semi-, un-, and anti-. Abovewater is reality. Underwater is semireality. Mindscapes are unreality. Antireality is outside everything.

GLASS - The knowledge and trade of this substance is strictly prohibited, thought that rarely stops anybody. Skientists weave it.

CRYSTAL - The naturally-occurring form of glass, being concentrated deposits of reality. Safer and more pleasant than glass, though long exposure is not recommended. Considered to be lucky, small, impure crystals known as "chit" are used as currency.

LETHALITY - Despite the theoretical immortality life underwater brings, in practice it's rare to survive much longer than a few months or years. There's the native fauna: generally large angry crabs, large angry sharks, etc. There's the sorta-native kinda-fauna: the teeth of nightmare beasts aren't real, but do feel it. There's the people-- nearly all armed and often tetchy (or worse, bored). Survive all that and you'll contend with madness and the very real tendency to disappear for no reason.

SOCIETY - How many people are underwater? It's impossible to say: maybe a thousand, maybe ten or fifty times that. But they do tend to stick together. Tiny, mobile camps pockmark the more desolate areas, while towns and villages spring up near drop sites or defensible areas. There's only a handful of large cities-- the biggest and most coveted is Wind City to the northwest, and most 'civilization' lies in that direction.
You live in a Base Camp with 30 or so others, though the number changes often. The town of Lindews' Landing is a 10-minute hike east.