One of the best bonuses included in the price of a Eurailpass for trains, is the included Lake Lucerne boat cruises. There are about 20 boats that cruise the lake there, of which 5 are old fashioned nostalgic paddle steamers. Lake Lucerne is about 38 kilometers long so there are many options for stopping at different towns, and catching the next boat back to make the trip as long or as short as you wish. The shortest trip is to Meggan that only takes about an hour if you're in a hurry but want to take a nice ride on the lake. The trips are a great way to enjoy the beautiful lake at a slow pace. The boats have first and second class sections, but the Eurailpass includes second class passage. First class is usually at the upper deck. Also there's either a restaurant or a bistro on board usually.
Cruise on Lake Lucerne are a great way to enjoy the beauty of the area around Lucerne.