This picture is one of a series of photos from Fontainebleau State Park in Mandeville, Louisiana. It was taken from the pier at the beach on Lake Pontchartrain at a very long way from those sailboats. You can see the Causeway bridge behind them.

Sizes here are (in inches): small - 10 x 7 1/2, medium - 20 x 15, large - 30 x 22 1/2