Those who were on the boat say that the normally sedentary animal plunged from a tree in an uncharacteristic flurry of movement – some even captured the rare event on video camera.
The sloth appeared at first to be a little bit dazed and confused by the nature of his dramatic entrance on board the ship but after a while regained enough composure to take in the sights along with the tour.
Experts on board say that the sloth must have been sleeping in a tree when he slipped and fell onto the boat.
On average sloths sleep between 15 and 20 hours a day and have been found with algae growing in places on their fur.