Since they nerfed the crypts spawning rate, cos of all the iron in Mistlands, I think it was like 430 down to 140 odd, your later generated seeds will have the crypts further spread out, so you're probably better off exploring the swamps after you kill the great unclean one and get the wishbone, never leave any muddy pile behind, get the iron pick axe first, and always take some iron on every boat ride so you can build the stonecutter and forge and stuff at safe spots. And build repair stations, just a table, along sailing routes you're going to use a lot. Good luck.