Summerland Key Cove Airport (ICAO: FD51) is a private seaplane base located in Summerland Key, Monroe County, Florida, United States. It sits within the Florida Keys island chain, southwest of Marathon and northeast of Key West, serving general aviation and seaplane operations. The facility is a water-based aerodrome, meaning it does not feature conventional paved runways but instead uses the surrounding cove waters as its operational area. It is privately owned and not open to the general public without prior permission. As a small private seaplane base, it has no scheduled commercial airline service, no terminal building, and no public ground transportation infrastructure. It primarily serves local recreational and private pilots familiar with seaplane operations.