Best riding spots in Jacksonville, Fl - non saltwater

Looking for some advise for a friend moving to Jacksonville, Fl. The catch - he bought a boat over the winter to use in Freshwater here, and has just been relocated down to FL for work. Now that he is moving, he wants to take the boat but it is not saltwater Series, (2006 MC). Anybody got advice on some good places to go down there, and/ or rinsing procedures afterwards.

Thanks!