Historic Spanish Point executive director John McCarthy will discuss Sarasota's maritime heritage during a presentation that begins at 2 p.m. Friday, May 18, at Alderman Oaks, 727 Hudson Ave., Sarasota. McCarthy's program will focus on the waters of Sarasota and will include a history of local sailboats, steamboats, powerboats and yachts. McCarthy will also explore the history of local bays and waterways and explain the origins of the name of all of the local barrier islands. RSVP online.