Alaska

Alaska is the cruise most people remember for its scenery rather than its ports. Ships spend a day or more sailing slowly past tidewater glaciers, and the towns along the way, such as Juneau, Ketchikan, Skagway and Sitka, are small enough to walk, with whale watching, floatplane trips and gold-rush railroads within easy reach.

There are two main ways to do it. Inside Passage round trips, usually seven nights from Seattle or Vancouver, follow the sheltered channels of Southeast Alaska and bring you back to where you started, which keeps flights simple. One-way cruises across the Gulf of Alaska, between Vancouver and Seward or Whittier, go farther north to the big glaciers around Prince William Sound and finish near Anchorage, which makes it easy to add a land trip to Denali.

The season runs from May to September. June, July and August bring the warmest weather and the longest days, along with the most visitors. May and September are quieter and often less expensive; May tends to be drier, while September brings more rain and the first fall color. Wildlife is good all season.

The choice of line matters more in Alaska than almost anywhere. Some lines have sailed here for decades and run their own lodges, railcars and land tours; others bring big-ship entertainment north for the summer. Ship size shapes the trip too: smaller ships reach narrower fjords and quieter towns, while larger ships offer more on board and often lower fares.

Alaska works especially well for families traveling across generations. The scenery holds everyone's attention, the pace is gentle, and excursions range from easy train rides to helicopter landings on a glacier.