On Carnival, you WILL have a $10 per person/per day charge show up on the very first day for tips. You have the option of taking off this amount and tipping the old-fashioned way, as well as raising or lowering the amount.
If you secure your sign and sail by using a credit card, there IS a hold placed on that credit card for about $200. At the end of the cruise, the amount you spent on your sign and sail is billed directly to your card, unless you settle up at the pursers with cash.
And yes, you can also choose to use a cash deposit instead of a credit card to secure your sign and sail
Carnival Elation March 11
Carnival Imagination Sept 07
Carniival Sensation Dec 06
RCI Sovereign of the Seas Sept 06
Carnival Miracle Sept 05
Carnival Glory Sept 04
Carnival Fantasy Jan 04