Castaways hold on to a handle with a rope wrapped around it (in Panama they just held onto ropes). At the end of the rope is a bucket that contains a percentage of the contestants body weight. As the challenge goes on, the rope will begin to unspool, making it harder to keep the bucket in the air. The last castaway remaining in the challenge win.
History
The challenge debuted in Panama as the episode 12 Immunity Challenge. The contestants were suspended over water ,when they let go of their body weight they would fall into the water. Terry Deitz won the challenge, winning his fourth straight Immunity Challenge.
The challenge re-appeared in Philippines as the first challenge of the merge, when Carter defeated the men and Denise defeated the women to win immunity.
In Blood vs. Water, the final 7 chose whether to eat or compete. Ciera, Gervase, and Tyson opted to eat, while the other four chose to partake in the challenge. In a tight struggle to win, Monica ended up beating Hayden, winning her third immunity challenge since the merge.
The challenge was used as the Final 8 in Survivor: Worlds Apart, when the last man and the last woman standing would be given Immunity. After a close battle between Carolyn and Shirin for the women and Mike and Rodney for the men, Carolyn and Mike won immunity and were safe at the next Tribal Council.