The five Great Lakes of North America are Lake Superior, Lake Michigan, Lake Huron, Lake Erie, and Lake Ontario. Together, they form the largest group of freshwater lakes on Earth by total area, containing about 21% of the world's surface fresh water. A common mnemonic to remember them is the word HOMES (Huron, Ontario, Michigan, Erie, Superior). Lake Superior is the largest and deepest, so massive that it could hold the water of all the other Great Lakes plus three additional Lake Eries. Lake Michigan is the only one located entirely within the United States, while the others share a border with Canada. Lake Huron is known for having the longest shoreline of any of the Great Lakes, including the world's largest freshwater island, Manitoulin Island. Lake Erie is the shallowest and warmest, making it highly productive for fishing but also the most sensitive to environmental changes. Finally, Lake Ontario is the smallest in surface area but much deeper than Erie, serving as the outlet to the Atlantic Ocean via the St. Lawrence River. These "inland seas" are so large they even have their own weather patterns and "Great Lakes shipwrecks" history.