Well when they were booked on the cruise their bank balance was say $X. After cancelling it is $X+10000. Then a future cruise voucher for $10000 dollars Now if yo wanted to book another cruise you effectively have twice the money to do so than what you had to book the cruise you had just cancelled.
Now it depends on the cruise line but when we have had future cruise vouchers from Silversea for cancelled cruises we were able to use them for cruises already booked but not paid for in full.
However if you have to book a completely new cruise these days it is invariably more expensive than the one you have just cancelled.
So you had $10000 to book a cruise. As a result of cancelling you now have $20000 to book a cruise. So to me that makes sense that you think you have doubled your money.
