The Boathouse in Prospect Park in Brooklyn is an example of how the Gustavino Company offered their design "suggestions" to the arthitectural firms, who in turn adopted Guastavino designs with few changes. The Boathouse was designed by the arhitectural firm Helmle and Huberty. This photograph of the interior depicts an example of a "flat vault" with an opening for a staircase. Photo © Michael Freeman. Courtesy of the Museum of the City of New York