Miami Seaplane Base (IATA: MPB, FAA LID: X44) is a public-use seaplane base located 2 miles (3.2 km) east of the central business district of Miami on Watson Island in Miami-Dade County, Florida, United States.

Its scheduled and other flights by flying boats and amphibian aircraft served many points in the Bahamas and other nearby destinations.

Chalk's moved its flights to its main engineering and operating base at Fort Lauderdale-Hollywood International Airport after the attacks of September 11, 2001, because of security concerns around PortMiami and increased helicopter traffic around Watson Island.

On December 19, 2005, Chalk's Ocean Airways Flight 101,a Grumman G-73T Turbine Mallard, crashed off of Miami Beach, Florida.

[2]: vii On July 1, 2018, a Tropic Ocean Airways Cessna 185 crashed on landing into the Miami Seaplane base when the aircraft nosed over into the water.