Duncan and Louise
At one point on this calm section of the river, Stefan swam underwater and beneath my boat to grab my leg. I freaked for about 2 seconds until I realized that it was him. To make him pay for his sins, he towed my boat around the group so that I could take photos of everyone. Being a water polo player, he rose to the challenge and brought me from the front of the group to the back.
On the return trip to the front of the queue, Stefan and I became the "Biscuit Boat." I brought two buckets of biscuits (small cookies for the U.S. audience) on the trip, and we gave each person that wanted a biscuit. We said that they were "fresh out of the oven" due to the heat. Everyone enjoyed, and it was great fun.
When we offered Duncan and Louise their biscuits, I tried to covertly swipe Duncan's water gun. Unfortunately, it was secured so well to his croc that it broke.