Hey Old Salt, congrats on 40 years and especially that new knee.  It's amazing what they can do these days when it comes to joint replacement.  I was out of canoeing (hell I could barely pull my socks on) for 15 years becasue of my hips.  About 6 years ago I had my second hip replaced and I suddenly got 20 years younger.  Three months after that second surgery I was hiking with my wife in Algonquin and I realized, "I can do this again!"  What a blessing, I'm hopping around now like a young gazelle and so grateful to be able to get back into the bush again.  My wife and I will be doing our first (hard to believe after all these years of tripping) trip into the Q this summer -  three weeks from the middle of August.  I hope your new knee gives you the same pleasure every day as I get from my hips.  Stay in shape, my friend, and you'll have 40 years more.