The couple, who has reportedly been going trough a hard time due to their busy schedules, spared no expense for the getaway.
In addition to staying in a private villa at the Sandy Lane resort, the "Mirrors" singer also rented a $1,125-per-day catamaran on March 14.
"Justin wasn't very good at wakeboarding," an eyewitness told Us Weekly. "Jessica was much better!"
The getaway comes after months of speculation regarding the couple's future, but according to the source, the duo "looked madly in love as they joked around."
You can check out pictures from Timberlake and Biel's Barbados vacation here.