Low water. Running the usual moves, I made it past the guard rocks (usually guard waves in normal levels) I was pointed to go through the nozzle, ~5 feet from it. Instead of continuing on a forward trajectory as usual, the hydralics seemed to suck me backwards and slam me against the right house sized rock. Knowing there was a sieve down there and not feeling confident about my roll up against a rock, I panicked and swam. There was an immediate pull of hydralics underwater, likely through the sieve so I could not get my head up, I was drowning. I reached up and felt a boat bow, grabed it and pulled my head up with one hand, other hand on rock. It was MY boat and it was going under, the hand hold did not last. With all my might, I smeared up on the rock, shoulder to water level. It was difficult, strong sucking "down the toilet hole." The boat came under my feet and it hesitated there allowing me some rest. My hips were forceably flexed along the curve of the rock so I struggled to remain above water, then Helene and Steve were on the downstream side of the rock. The boat went through, I was going down. Helene threw a rope which allowed me to get my breast to water level. Steve jumped up on the rock and grabbed my PFD shoulders. At first he was unable to pull me up, hips flexed, legs getting sucked down and through; I thought we would need to cut off my legs to get me up. We just stayed there for a minute then there was a "reverse surge" that allowed my legs slack water and Steve pulled me out, onto the rock, terra firma.
We ran the first Class 4 rapid (Mercury?) and met in the river left eddy above the Nozzle. I had only run the river once before and it was Steve's first time - though well within our abilities, it was not a familiar place. I knew that there was a sieve somewhere in this rapid called Nozzle, but wasn't sure where. Mary went first, and she flipped near the entrance of the Nozzle where you're supposed to go between two very large boulders. I was surprised to see how fast she was being pushed to the right upstream of the right side rock while upside down, which didn't seem right since that rock seemed connected to the rest of the rocks on shore. There shouldn't be current going in that direction. Steve and I immediately pulled out of the eddy and headed downstream. I thought about eddying above on the right to be above the sieve, but being unfamiliar I didn't want to end up in the sieve too so I decided to make the "regular" move and eddy out behind the rock. We immediately saw Mary's face above the water, hugging what seemed like a submerged log or a rock bridge spanning a narrow channel between that right big rock and the shore. The channel was very narrow (2-3 feet?)
She was very calm and clearly said "I need help". Still in my boat, I threw her my rope and wrapped the other side of the rope around a rock next to me between her end and my end since I was still in my boat and not in a stable place. I figured at least she could hang on to the rope until we got situated. Steve jumped out of his boat and stood on the rock bridge that creates the sieve and grabbed her PFD. Her boat was nowhere to be seen (I found out later she was standing on it!) but a little while later, while Steve was still hanging on to her by her PDF, the boat came popping up from underwater in the eddy below us. Shortly after, Steve was able to pull her out and while she rested a little on the rock, I went to secure the boat. There was no place to get back in the boat in that river right eddy, so it took some work getting her boat and her (swimming) across to the river left because the eddy lines were powerful. Through the whole rescue, Mary kept her cool and clearly communicated with us so we knew how she was stuck and what was going on underwater. That made a very big difference. Thankfully, after all this we were done with the hard rapids and got to the take-out without any more incidents.