Many thanks for the quick and thoughtful responses. I will definitely check with the whitewater crowd and post back what I learn. Having had bilateral total hip arthroplasty a decade ago, I appreciate Crabstick;s advice. Having been forced to give up cycling the year prior, I held off hip replacements until I was walking with two canes, could barely get my ski onto the car and into the water, and seemed to be deriving most of my calories from ibuprofen just to be able to sleep through the night. Arguably, I waited longer than I should have on the hips. But the transformation after hip replacements was amazing. I don't run or play tennis, but I can road bike and mountain bike as hard as I want, backpack and hike all I want, and leg drive in the ski is better than ever. But, hips are big, stable joints that move in a much simpler range of motion than shoulders. So, I'm trying to figure out what to do with my right shoulder. My x-rays show almost no space in the joint, and I'm told the deterioration is far worse than most folks who have replacement surgery. I'm starting to snack on ibuprofen a bit to sleep and the pain is starting to limit small daily activities - can't throw the frisbee for the dog to catch; can't raise my arm laterally to write on a desktop (need to put the pad in my lap), etc. Still able to do 2 hour ocean paddles and not suffering too much for it - keeping those elbows as low as possible and relying on hip rotation as much as possible - but the pain is increasing quickly and it's obvious where this is going. Again, many thanks for the advice and well wishes.