My SIL and I are taking a quilting cruise in May! I live in Texas and she lives in California, so it will be fun in many ways. We selected a cruise based on a class I took at Houston this year. The teacher was Charlotte Angotti and the cruise is through Stitchin Heaven (stitchinheaventravel.com). There are several cruises to choose from. We are doing Girlfriends at Sea, May 1-8 cruising the Western Carribean. There will be 3 teachers and 3 classes.
You said you are looking to take a cruise alone. If you take this one, look for the SILs and you'll have two friends from the git-go! PM me if you want more info.