My PCs are currently level 13 and playing through "Age of Worms", which, for those unfamiliar with it, is a fine adventure path. The PCs have decided to search for another piece of the Rod of Seven Parts.
One of the PCs hails from a family that used to be nobles in a coastal city until they got to big for their britches, got on the wrong side of a god, and the city sunk into the ocean. A fragment of the rod was in their treasury.
I have my hands full with running AoW in our custom setting so I'm looking for a good mid-high level aquatic adventure to adapt. Characters are currently level 13. Preferably something with a sunken ruins type of setting but not necessarily. I can adapt.
Any suggestions?