The Doge’s Palace (Palazzo Ducale) is on Piazza San Marco at the political and tourism heart of Venice. All travelers, including thousands of day trippers, end up here eventually. Fortunately, the palace is far less busy than the square.
Many boats stop at the various San Marco or San Zaccharia landings, including Vaporetto Lines from the station and Alilaguna from the airport. Traveling time from Piazale Roma or Santa Lucia train station is around 45 minutes by boat via the Grand Canal, while walking takes about the same time (if not getting lost).