Grand Lake St. Marys Seaplane Base is a public use seaplane base located five nautical miles (9 km) southwest of the central business district of St. Marys, a city in Auglaize County, Ohio, United States. It is owned by the Ohio Division of Parks & Recreation and is located on Grand Lake St. Marys, a lake and state park in Ohio.Facilities and aircraftGrand Lake St. Marys Seaplane Base covers an area of 643acre at an elevation of 871 feet (265 m) above mean sea level. It has one seaplane landing area designated 9/27 and measuring 7,000 x 4,000 ft (2,134 x 1,219 m).
