My old SA GPX 5 wt. line was looking a little checked and cracked so I replaced it with the SA Sharkskin Trout WT. I've fished it a couple times now on the Deschutes. The Sharkskin really does have impressive shooting characteristics and I was able to make nice roll casts shooting line. Maybe I was able to roll cast so easily because of all the spey casting I've done for the last year, but I think the new line made a big difference. But I had a hard time keeping the tip floating. It seemed like I had to keep dressing it about every 15 minutes. Used the SA line dressing. Used a mono leader, same as before. The old GPX seemed to float much better with that reservoir tip. What am I doing wrong?