I find a nice site with some volcanic rock, stock search finds a decent cavern (unexplored as of yet, thank you forbidden clothing!) about 116 levels down. I'm by an ocean, on land with trees, temperate climate, somehow there is a bit of fish and I can eek out a decent living. By dealing with elves I picked up war elephants and leopards (both in breeding pairs!). They should hold off until enemies arrive (baby snatchers have been spotted). I'm doing well, and decide it would be nice to add in a second stairwell as the main entrance was getting crowded. I get a "damp stone" warning, ignore it since it's raining. And then, post-fact, realize I'd originally dug into a rock vein to pierce the lower levels--this allowed me to sidestep the aquifers on the way down. Well, now I have an aquifer flooding into my base. I arduously close down all mining routes and try to dig a channel with a wall behind it (if the dwarves are caught they'll just dig a stairway to safety).The builders say the water is too deep! (2/7) and my two legendary miners immediately go on break upon hearing of a massive wall of water coming their way. The third miner, a newbie, somehow suffers a bout of narcolepsy--which was NOT mentioned in his [z]. Since he was on the lowest level (the quarry), and now has 4/7 water blocking the exit, he just yawns and takes a nap in the face of a fountain of gushing water. Fun is currently in progress. I think, if he wakes up, he should dig down to find that cavern..
Facepalm knowledge: Maybe a little travel inefficiency is a good thing. It beats work inefficiency, which is arguably just as disastrous. Wish I had some magma, I'd sort this right out.