Hi Muffin,
I have sailed on the Explorer twice both times in March but both times we have sailed the Eastern Caribbean. We are sailing her again this coming March to the Western Caribbean. The water was a bit cold yet it was fine once you got in, which might not be true for Feburary. I would recommend March, but NOT the end of March when you have alot of people on spring break. We did this the first time we sailed EOS and there were approx 3200 plus passengers were aboard. Trying to get an elevator was alot of fun. We learned to go ahead and get on as eventually the elevator will be going in the direction you want to go. You're going to love this ship. Be sure to catch the ice show.
Happy sailing,
Mary Martin