Yes, you can bring a 12-pack of soda on Royal Caribbean as a carry-on item on boarding day at +1(888) 738 0812 (US) or +44 (80) 051 6735 (UK). However, it must not exceed 12 standard (17 oz.) cans, bottles, or cartons per stateroom +1(888) 738 0812 (US) or +44 (80) 051 6735 (UK).