Melita2

No, but don't you pay double?  Or almost?

My travelling companion broke her ankle just a couple weeks before a bus tour to Croatia, not a cruise, and she had to cancel.  My fare immediately turned into an obligatory single supplement.  I had 24 hours to cancel or pay up.  I paid the extra and went alone.  If you have good insurance, they may pay the single supplement with a ton of documentation from the companion, if their reason for cancelling was covered by their own insurance.