This pair was "swimming" in the little pond at the bottom of the medicinal herb garden. For 20 minutes or so, they moved along the water scooping algae off the sides of the pond with their beaks (perfectly shaped for algae scooping!) After these 20 minutes they hoisted themselves out of the water and waddled cautiously past me to the slightly larger pond at my back where they dunked themselves, seemingly bathing before laying down for a nap at the pool side.