In 1885, construction began on the second-largest deepwater harbor in the world--second only to Cherbourg, France--to be called the Sandy Bay National Harbor of Refuge. It would consist of a giant 9,000-foot granite breakwater that would offer safe harbor to over 5,000 vessels and enclose an area of 1,600 acres. As it was being built, the US North Atlantic Fleet began making annual visits to Rockport with its newest and largest warships, including most of Teddy Roosevelt's Great White Fleet. These visits were designed to facilitate the fleet's training maneuvers in the waters of Cape Ann as well as demonstrate the need for a protected harbor for national defense and security. Over a 30-year period, 21 annual visits occurred with more than 100 naval vessels, including battleships, cruisers, torpedo destroyers, submarines, dispatch yachts, and other support craft, anchoring in Sandy Bay Harbor.