The Fathom Five National Marine Park is located right off the rocky shores of Tobermory and boasts of being one of best fresh water dive sites in the world. This underwater playground consists of 22 shipwrecks and a variety of neat geological features such as caves, cliffs and overhangs. While the pristine turquoise waters of Georgian Bay offers phenomenal visibility for fresh water diving, the only catch is that the water is cold. Very cold.