I think that most of the ships do have ATMs but don't be surprised at 1) the fee for using them and 2) They will likely be empty by the 4th or 5th day of your cruise and have a note posted that they are out of service.
Rather than use the ATM I bring travelers checks. You can cash them at the Purser' s Desk and if you don't use them all, just bring them home and redeposit into your bank account.
__________________
Celebrity Century 1/09
Carnival Destiny 10/07
Carnival Destiny 9/06
Monarch of the Seas 3/06
Carnival Inspiration 8/05
Carnival Miracle 4/05
Carnival Inspiration 4/04
Sovereign of the Seas 4/03
Inspiration and Victory have them and are conveniently located near the CASINO!!! I've heard the extra charges are outrageous though. I agree with Darcy, take a few traveler's checks. The ones on our ships never had "Out of Order" signs on them.
Last cruise we were on the ATM was by the pursers desk and right outside the Casino .....GO FIGURE! I guess they want to suck in your money from the ATM