If you have a big budget, my husband and I loved the Uncruise line (formerly Innersea Discoveries). We took the Ketchikan-Juneau itinerary in 2012 and are taking the reverse itinerary next month. Our ship held only 73 passengers and the focus was more on nature and small villages than shopping and gambling. They also had a wonderful mix of activities. My husband is 75 and I'm 61; he's got a bit of a balance problem and I can climb over logs and uphill to caves. We both had a great time because they're careful about explaining exactly what's involved, whether it's sitting in a skiff on the way to the glaciers, or snorkeling in 42-degree water. (Yeah, I did that.)

Definitely different from the big boats.