From Shore To Sea (written by Brandon Hodge) is a nifty little adventure. Set on the coast (of Cheliax, but could be placed anywhere), it has the PCs investigate strange happenings at a small fishing village. Villagers have been disappearing, and there are rumors of strange “fish-men” stalking about. Yes, Paizo’s love of Lovecraftian stuff is in full swing here.
It doesn’t directly follow an “Innsmouth” plot, though, even though that has obviously been some influence. Events lead the PCs to an extremely strange island some ways offshore, and unless they are careful they might find themselves changed in some ways… permanently. The island is quite inventively designed, and the main plot is decent enough as a driving force. Also, the backstory has some nice “local traditions” that are linked to the happenings, and should cause some headaches for the PCs if they hear about them. The main “bad guy” has a fair chance of escaping and returning in the future as a recurring villain, which is always a nice touch. There are lots of small nifty details in this module, and in general I’d rate it as one of the better Paizo standalone modules.