My wife and I are planning a 7-night Eastern Caribbean RCI Explorer of the Seas from March 19th to 26th.
Will this be a busy week? Is this still considered spring break? Will there be lots of college/high school kids, or predominately adults as spring break is over?
Spring break runs from mid-March to mid-April, depending on where you are in the country. The week you mentioned is likely to be quite busy with folks on spring break. Our local spring break is the following week, so you will definitely not be past it!