LAST EDITED ON 12-04-15 AT 05:34 PM (EST)Thanks Georganna! The top shot you brought over appears to be a different land-based challenge. You can see that Kelley's top and hair are different vs. all the rest of the caps, which are from the water obstacle course challenge.
Based on the wording of the CBS teaser, it appears that the water challenge is IC , so the land-based/top photo must be RC.
In the video, you can see that Spencer's and Kelley's hair are wet, so I'm thinking they're done and just waiting on the beach when Tasha calls for help. If they run it like the past, I don't think there's puzzle at the end. (See link above from Survivor Wiki on how "Troubled Waters" works.)
Looks like Kimmi is carrying one of the flags, which seems to confirm that this is the Trouble Waters challenge.
ETA: Just reread the Survivor Wiki for the Trouble Water challenge, and all they have to do is place their 3 flags in a holders on the beach to win. No puzzle in the past. So it's mainly all about running the obstacle course quickly and keeping your balance as you jump from station to station to get back to the beach.