Industry Experts & Guests 50+ - Theme Cruises & Small Ships

Working on a story for AARP Magazine about THEME CRUISES and looking for several different sources. Comment here if you know someone who comes to mind. I'm looking for: 1. Industry experts who can comment on the history, development, and current state of the THEME cruise industry, including their appeal to 50+ people. Why do theme cruises attract travelers who wouldn't otherwise take a cruise? 2. Guests and/or onboard talent who have sailed on a LITERARY themed cruise (book clubs, writing workshops, author-hosted). Looking for two individuals over the age of 50. 3. Special smaller cruises that offer an escape from the typical crowds and activities. These are smaller cruise lines - including river cruises - that are NOT the types of lines to offer big theme cruises. But, they do have some special voyages. What are those sailings. Why are these smaller ship cruises special/different in the marketplace of cruising? Pictured: Scenes from sailing Portugal's Duoro River with Riviera Travel