The song is an upbeat, reggae-influenced tune[1] about a man who wants to relax on a beach as a "castaway".
Critical reception
An uncredited review from Taste of Country was positive, saying that "The textured vocals are much more compelling than anything from the arrangement, although it’s pretty tough not to enjoy the groove the Zac Brown Band band are laying down in 'Castaway.' It’s actually been some time since ZBB released an island-flavored single, and the timing couldn’t be better for this brand of country music."[1]
^Jekyll + Hyde (CD booklet). Zac Brown Band. John Varvatos/BMLG/Southern Ground/Republic. 2015. B0022962-02.{{cite AV media notes}}: CS1 maint: others in cite AV media (notes) (link)