Easter is in March so the spring break will be around that time. My son is in college and his starts 3/13/03, my daughter is in high school and hers is a week later. I do believe that 4/20 will be AOK.
It just depends on where you live. We're on the West Coast and our Spring Break is always the week after Easter. Easter is on 4/20 next year, I know because we are booked with my 3 kids on the Navigator sailing 4/19. I think a lot of the East Coast have Spring Break in March.
I think yoiu will definitely see some Spring Break action that week, but probably mostly families.
Well Dolores our spring break for the east coasters was always around Easter time also but this year it's not because Easter is soo late, so for us east coasters the spring break for college is mid March as my son is in college in NC and high school the same. I guess you'll be stuck with spring breakers from the West Coast, hopefully there won't be too many of them!