The 21-year-old country singer, who recently split with Jake Gyllenhaal, guest starred on the Allure of the Seas liner in the Caribbean.
She told ETOnline.com, 'The cool thing about playing the AquaTheater is that the crowd is in front of you, but they're also all on their balconies and... they're everywhere. It's very exciting.
'People had decked out their balconies and were wearing shirts and holding up banners and it was so sweet. I love feeling that love from the fans and they've been so wonderful to me.'