Cross The John Ringling Causeway (Fl-789), Crossing The Bridge Over Sarasota Bay. When You Reach St Armands Circle, Continue North On Fl-789, Which Becomes Gulf Of Mexico Drive As You Enter Longboat Key. Drive For About 8 Miles Along Gulf Of Mexico Drive. Seaplace Will Be On Your Left - 1935 Gulf Of Mexico Drive. Register At Guard Gate And He Will Direct You To G7-402