Looks like a "move stuff from here to there" kind of challenge. They've moved water in the past, but I don't think those baskets will carry much water. Who knows what they're gonna carry. Looks like they have to stay on the floating walkways. You can clearly see it come to a Y-shaped intersection, where the heavy traffic/wrestling is going on. Give big Ted (former pro football lineman) the edge in any wrestling/pushing contests.
In pix 2 & 3, it looks like Shii Ann is carring a small bag/basket/coconut??? Maybe a small water container? Water container is my best guess.
In pix 8 & 9, it looks like this same item is falling out of Brian's basket, about to hit the water. Is this what they're transporting across a floating, criss-crossing obstacle course? Pretty hard to tell from the pix, but it's a decent guess at this point. Looks like they try to fill up the baskets with water containers, to get more of them across faster. I'm guessing that if they hit the water, they're no good & have to go back for more.