Fathom Five, Canada’s first national marine park, consists of 20 islands to the north and east of the Bruce Peninsula, 130 square kilometres of surface water, the ecosystem reaching 200 metres below, and the park’s tiny landbase at Tobermory Harbour. Composed of green islands, lake bottoms and clear cold water, it is representative of the Georgian Bay Marine region. The islands of Fathom Five, created where the Niagara escarpment dips underwater off the peninsula, comprise the northernmost park in a system of over 100 escarpment parks and protected areas linked by the Bruce Trail. Established in 1987, along with the Bruce Peninsula National Park, it protects the on- and off-shore landscape renowned for its scenic beauty, dramatic escarpment topography, and remarkable collection of 21 historic shipwrecks, some just a few metres from shore and all within the park’s crystal clear waters. The human history evoked by the spectacle of shipwrecks that make for some of the best diving in North America is no more fascinating than the breathtaking story told by this underwater topography.