Port Upgrades that are not "Upgrades"

[calngavinsmom]

Hello all! I have a cruise booked for October in a 4E. I am really hoping to snag a 5E before we go but if I can't, would I be able to "downgrade" at port if there is something available? How would that work? Would we have to pay anything, or nothing? Any insight would be appreciated!

Take care!
Tara