Having never built an ocean fort before, I want to make sure I pick a good site to embark on before doing this. So what should I look for when choosing my site to ensure I'll find mermaids there?
As far as I know, they live in good oceans.
Also, if I were to build glass tubes filled with magma underwater, would the mermaids see it and avoid it?
In short, no. That makes no sense whatsoever, in current AI-terms (though it would, of course, make sense in real life), at least the way I understand this.
I've just started a new game, at last. I've modded my civilizations to have non-overlapping active seasons. Because the way sieges and trading currently work, having several sieges per year (I'm currently using 7 hostile civs) effectively keeps me from trading unless I'm incredibly lucky. Accordingly, I gave all my hostiles active seasons other than autumn so I could trade in peace.
It's now early autumn, and guess what? A vile force of fucking darkness has arrived. What do I do to make this goddamn game actually use my active season settings, instead of overriding them willy nilly?
Currently, the only solution seems to be disabling invaders altogether for the years you want to do some trading, which is a half-measure at best. Not to mention that it doesn't work as reliably as I expected (last time I tried, I still got invaders in the year following my disabling of them). Of course the mere fact that traders, who only come around once a year, will completely bypass your location when you're being attacked, instead of waiting somewhere safe is ridiculous.