I had the same experience for my upcoming Aug. 6 cruise. I needed 5 spots, but there were only 2 left. I emailed the shore excursion department (Shorex@RCCL.com) & got a very quick response. The person who responded was Lisseth Steiger. She said that she would check with the tour operator to see if they could add 3 more spots. Before she heard back, though, I decided to book something else instead, and I just cancelled my RCCL booking today.