The incident took place in a marine nature reserve near Roca Partida, one of Mexico’s Revillagigedo Islands, some 250 miles to the southeast of the resort town of Cabo San Lucas.
Divers discovered the 33-foot whale shark during a routine tourist trip.
The animal was entangled in ropes approximately 100 feet below the ocean’s surface.
Divemaster and cruise director Daniel Zapata and several other divers made two trips down to the slow-moving whale shark, first to check its condition, and then to remove the rope, which may have eventually killed the still-growing animal.
A large, deep scar could be seen on its back once the rope was removed, leading the divers to believe that the animal had been trapped for some time.