On ocean cruises, the cost of shore excursions will vary considerably from port to port and depending on the length and activity involved. Generally, you should allow about US$40 - 60 per person for a half day tour and US$100 - 150 pp for a full day tour including lunch. For ocean cruises, detailed shore excursion information and booking procedures are available on the cruise line website - if you wish to book your excursions in advance, you can do so online. On river cruises most shore excursions are usually included. Information on optional excursions will normally be provided on the riverboat.