Cruise lines make it easy to explore at the ports of call, selling organized shore excursions. Booking through your line is always the simplest way to buy a tour. But you also have the option of do-it-yourself activities and sightseeing, which can save you considerable money. This is a good choice if you have more time than budget, or if you want to get away from the crowds or see something not offered by the line. Here are some tips to get you started: