I have had 2 particular cases that apply.....
1- Pinned vertically with my bow sticking up in the air: Basically came around the corner and was heading in to a sieve and attempted to boof over the sieve into flowing water below.....pinned vertically and violently and luckily my stern propped up on some rocks. My body was alomost out of the water but the boat began to shift and sink. I basically climbed out onto nearby rocks.
2 - Pinned vertically with my bow submerged: Hit an undercut (that was submerged (barely) and pinned. I un-cocked my legs from the thigh braces immediately and tried to pull my knees toward my chest and get my feet on my seat without pulling my skirt. Then pulled the skirt and immediately stood up on the seat and jumped up to a nearby rock.
Both cases i was able to avoid the swim and both cases had a hell of a time trying to retrieve my boat.