River Cruises

In theory, any river cruise can be an active one, given that shore-centric itineraries allow passengers to pursue all manner of land-based activities. Many lines, particularly those plying Europe's rivers, already provide bicycles for their passengers. (And if they don't, you can always rent one in port.) But as competition in this fast-growing segment of the cruise market heats up, some lines are seeking to attract a broader -- and younger -- clientele by offering a greater scope of active and adventurous pursuits. Here's a look at some best-bet lines for river cruisers