Here's a quick review of a very well done Underwater setting for Pathfinder "Cerulean Seas Campaign setting". I own these myself, great for underwater adventures, I have also built the 3D towers for underwater battles which work pretty well in the few short test runs I've done with my son. If anyone is interested in checking it out let me know.
http://www.richplayingitforward.blogspot.com/2014/05/thank-you-emily-kubisz.html#more