With the exception of the Grand Banks and the Scotian Shelf, the Atlantic Marine Ecozone is defined by deep water. Its offshore boundary wanders along the edge of the eastern continental shelf and about half of the ecozone is located well out to sea. It begins in the Davis Strait, follows the Labrador Shelf south around the Flemish Cap seamount, takes in the Grand Banks, and comes ashore at the northeastern tip of Newfoundland's Avalon Peninsula. The inshore boundary encompasses all of Newfoundland's south coast and Nova Scotia's east coast, and extends into the Bay of Fundy and south to the Gulf of Maine. Icebergs seemingly the size of small mountains, with 90% of their mass underwater, are not uncommon and have been feared by mariners for centuries. Because of the danger of collisions with icebergs, sailors named the stretch of ocean from Greenland to the southern coast of Newfoundland "Iceberg Alley."