Have never had it on Carnival for that area, but have used it on both Princess and Holland America. At sea doesn't really matter what cruise line, the internet is at the mercy of location and conditions but my overall experience in caribbean has been good. But I should add I carry a small Acer Aspire laptop which has a nice wifi system so if you are going to be using a phone you may have signal issues in certain areas of the ship, just have to walk around looking for good bars...... On the cell phone of course