Yes Cruise Ships do have ATM machines on board the Cruise ship for passengers to use while on board the cruise ship to get cash.
However the ATM machine fees on Cruise ships are higher than the ATM fees are at port before you board the cruise ship.
So it's best to get cash at the ATM or your bank before you get onto the cruise ship to save money.
ATM machine fees on cruise ships can vary but are on average of $6.00 per transaction.
The Carnival Cruise Ship ATM transaction fees are 6.00 per transaction so be prepared to pay that fee if you want to access cash on the cruise ship.
You can also just use your credit card or debit card on the cruise ship for paying for meals and anything else you want to purchase without needing to use cash.