When you select a cruise and date, click on the date. Teh next page opens, showing the cruise and prices. At the top near the left, there is a tab for itenaries (sp). Click on that, and the map will show.
I had been trying to see the map by clicking on "See Full Itinerary" after selecting the cruise and getting to the "Select Departure Information" page. Never noticed the Itinerary tab on the top of that page (boy is my face red).
I like the way it's presented on the Celebrity website - you can see the maps displayed as you're perusing the cruises. Just thought RCI would be doing something similiar.