Clif,
I have been wearing the Teva sandals since they came out some 15 or more years ago. Of the three or four pairs I've owned, the first several pairs were the earlier, flatter-soled models. I liked them best, due to my long feet, they were the less bulky in my kayaks.
At any rate, I think by the second and third pair, they started developing delamination problems. At first I tried water-based contact cement, then petroleum-based contact cement but it seemed to fail fairly shortly. Since then, I have happily settled on using Aqua Seal, it's been just the best!
Sometimes I would just have some short delaminations at various places around the sole. I would just enlarge them a little with my knife, pry them open, squirt in some Aqua Seal, then clamp the area overnight. Other times the delaminations have been severe enough that I took my knife and finished
completely seperating the sole layers, cleaned them well, and roughed them with course sandpaper for the best bond, then applied Aqua Seal to all surfaces, then clamped both pairs in between two boards for a day or two. ( if it weren't for the straps and buckles getting in the way, this clamping technique would be even better.)
Over the years I have come to understand the shortfalls of wearing open-toed sandals on the river... Marlo gave me a really nice pair of Keen shoes a couple of years ago that are so much better, and real comfortable, but with them comes enough length and bulk that I just can't fit them in any of my kayaks except my largest Rec. boat. Wouldn't be an issue if I paddled a canoe

This is probably more than you wanted, but I do like my old Tevas, they have been pretty reliable. I just wish the company would have paid more attention to this detail to begin with.
Best Regards
Jim