I think the clarity needs to be in the difference between college spring break and Easter Spring Break (K-12).
This year, these 2 breaks are very close because of how early Easter is. However, there is no overlap here.
College Spring Break will yearly follow the relative dates in the link provided (early march through late march).
Easter Break Varies with.....Easter.
The booze cruise concern should come with the college spring break, in my opinion.
The rowdy kids (teens) will happen on the Easter Break Cruises.
The overcrowding will happen on both, but more likely on Easter Break (since families travel more than college kids - on cruises that is).