Wow, your Explorer cruise is just around the corner, almost time to start the packing or at least get the luggage out of storage??? We were on Explorer a few weeks ago and it was by far the best cruise ever, you will love it. Here is a link to the review I wrote, to help you get more in the mood??
Try to sign up for the waverunner tour in Labadee, its a gas and well worth the money. If you like to lay out in the water, also sign up in advance for a water mat, they do sell out of those and they are a great way to just relax.
Catch all the shows, including the ice show, which you'll have to pick up the tickets for, no charge, but a much smaller area and not everyone can go at the same time, well worth seeing. Oh, yea and the parades, go see them too. Best advice, is to read through the "compass" every evening and decide what you want to do the next day, tons to do, enjoy!