You think you've skipped the bus tour of France or Germany or wherever in favor of a river cruise, right? It's true that ships often dock right in the middle of town, meaning easy access for your walking tour. But some key attractions, including vineyards and some UNESCO World Heritage sites, won't be right near port, which means you’ll be climbing onto a bus to see them. And remember, if water levels are low and ships can't travel on the river, your cruise will likely morph into a bus tour.

River ships are limited in size to the confines of the rivers — they need to fit into tight locks and get under low bridges. While the river companies creatively design the onboard spaces, the reality is you won't find a river ship in Europe that's larger than 38 feet wide and 443 feet long. You're cabin won't be particularly large either (book a suite if you need space).

River cruises are basically floating packaged tours. You pay upfront for accommodations, meals, and shore excursions, along with other included niceties such as wine and beer with meals (on some lines even free cocktails) and complimentary Wi-Fi. It's great for those who like their travel spoon-fed, but DIY types face a conundrum: Do you skip what you’ve already paid for in order to be able to do your own thing?

River ships typically carry fewer than 200 passengers, and sometimes less than 100. Dining is open seating, and hangout spaces are limited to the main lounge, dining room, and sun deck, and sometimes a small library or second lounge. So if you're not the social type, there's no place to hide. Come on board expecting to eat, drink, tour, and converse with a group.

River ships operate on a strict schedule, which often goes something like this: breakfast buffet, morning tour, lunch buffet, afternoon tour or cruising, cocktail hour or daily briefing at 6 pm, dinner at 7 pm, nighttime entertainment (typically a movie, folkloric show, or piano player), bed. Then repeat this the next day in a new port.

The river cruise crowd is mostly couples age 60 and up, sometimes way up. This doesn't mean someone younger won't have a great time — the "packaged" aspect of the experience can be appealing to any adult. But it does mean you should be prepared for tours to be conducted at a fairly slow pace, and for evenings to be quiet.