I got into an argument at work with a guy I work with about clear/blue flourescent line not being usable in really clear water because of it being visible to the fish. He said he uses it exclusively for 40 years and hasn't noticed any difference in fish catching between it and clear line. I disagree but am willing to be put in my place if I'm wrong. I have a strong track record trout fishing in water so clear you have to be careful when wading in it to avoid suddenly ending up deeper than you want to be. Cold mistake right there! I know for a fact that line choice makes a HUGE difference. Best year I ever had I was using 4lb clear Stren on my ultralite. It's hard for me to get away from the green Sensation though. Caught too many fish in gin clear water with moss all over the bottom where green line can be more invisible than clear. Now, my dad has a spool of 2lb clear blue he uses for leader because that's all they had in 2lb at the time of purchase. He catches fish and occasionally outfishes me but not often. I use a greenish Trout Magnet mono leader and it has proven to be better than anything I've ever used when it comes to fooling finnicky trout. Since flourocarbon sinks it's useless when a floating leader is part of the presentation.