Songfacts®:

• In this song, Zac Brown finds himself drifting in a post-breakup malaise, so he takes corrective action, buying a boat and taking a permanent vacation. When he's knee deep in the water, all is well.
• The song features trop-rock singer-songwriter Jimmy Buffett. Bassist John Driskell Hopkins explained to Billboard magazine that the collaboration happened as a result of a chance meeting in 2009. "We met him on a camping trip last year," he reported, "and just sat around the fire with him for awhile. That was a quick friendship. He's a real cat, really down to earth and doesn't have a whole lot of ego and just a super nice guy. We did a lot of vocals down at his place in Key West and he happened to come through, so we got him to sit in and it sounded great. It sounds like a Buffett song when he sings it. Whatever he sings sounds like a Buffett song, y'know?"
• Zac Brown wrote "Knee Deep" with his frequent collaborator Wyatt Durrette along with the band's keyboardist and guitarist Coy Bowles, and Nashville writer Jeffrey Steele ("What Hurts The Most"). Durrette told the Atlanta Journal-Constitution the song originated in the mid 2000s. "I had just broken up with a girl. I was just done. I just wanted to get the heck away," he said. "It's a happy song. But that first part, I needed to get away from the world. I needed to find some water. That's how the first verse and melody came about. I wrote the chorus and bridge with Zac. Jeffrey helped us out with the bridge. He helped us finish the song. We needed it. Coy helped write the second verse."
• The video was shot in and around the Costa Careyes Resort in Mexico between May 17 and 20, 2011. Directed by Darren Doane, it includes scenes on a private beach, in the pool area and under a coconut tree. Buffett's scenes were shot separately in the Florida Keys.
  
  The video marks the return of "Flody Boatwood," a character who first appeared in the Zac Brown Band video for "Toes." Flody, played by the band's sound guy Jake Bartol, likes to go in the water wearing beat-up sneakers and uncomfortably short cut-off jeans. In "Knee Deep," he's joined by two family members: "Brody Boatwood," played by ZBB guitarist Clay Cook; and Jody Boatwood, played by Juliette Lewis. She's known for her roles in films like Natural Born Killers and From Dusk till Dawn, but has also appeared in a handful of music videos, including Melissa Etheridge's "Come to My Window" and Thirty Seconds To Mars's "City of Angels."
• Released on Zac Brown Band's second major-label album You Get What You Give, "Knee Deep" topped the Country chart, marking the second #1 Country single for Jimmy Buffett. He previously reached the summit in 2003 with his Alan Jackson collaboration, "It's Five O'Clock Somewhere."