I found this picture of Skull Rapids on the American Whitewater page (with the following quotes). Skull Rapid is the most technical rapid in Westwater Canyon ("site of some epic mishaps") -- through the rapid you have to avoid Skull Hole ("a definite raft flipper") and then avoid the Room of Doom below it, a powerful eddy ("there have been cases where groups have actually had to dismantle their raft and portage up over the cliff").

We made it through Skull Rapids just fine.