With most shore excersions there is a guide that will explain, joke, etc. They will most likely deserve a tip and the bus driver a few bucks to each. In some cases the driver will also be the tour guide. When we did a tour to Dunns River Falls, we then had a guide from the falls take us up and he certainly will also be looking for a tip, again a few bucks. A good idea is to leave home with 20-30 single dollar bills to have handy for tips like these :-) Have a good cruise.