I was checking The legend and it appears that it is doing a Hawaii trip in early 2005, then Panama Canal in MArch, and off the Europe for? I so far have not found any cruises leaving San Diego on RCCL but will keep checking. There are cruises all year on RCCL to Mexico leaving from Los Angeles on the Vision of the Seas and the Monarch of the seas.. I will let you know if I find any more.
Just found out that RCCL has discontinued all service to Mexico from San Diego all together. The Legend has been repositioned and there is no other ship taking its place. Sorry. Maybe leave from Los angeles, or try the Carnival Spirit that is in San Diego for part of the year. I think it's there in the Winter and the Summer its in Alaska. Hope this helps.