Here's hoping there are some single gals on the Cruisemates.com message boards who will be going on the Explorer of the Seas 4/28. If not, be sure to go to the get acquainted party for singles the first night, and if you don't have any luck there, ask the maitre d' if he knows of any females dining alone and ask to be seated with them.
Another tip: Be sure to stay out on deck when the ship is leaving port. People who are "with" somone tend to be "with" that someone during this very exciting time. If you spot a solo lady at the railing...or a group of solo ladies, make your move.