My friend and I are going on a cruise later this year and Venice is the only place where we will actually be at port for 2 days. My question is, rather than pay to have an excursion through the cruiseline both days, we would rather do that one day and save the other day to explore on our own. Can anyone tell me how expensive or difficult it would be to get transportation from the port to the city centre and back again? This is our first time to Europe. Thanks in advance!