Pick up some of these indicators made by Float Master.
floatmasterco.net for more info.
Personally I think they are sick…and we at the CRO have no connection with the company whatsoever. Just sharing this out of the kindness of my heart.
These things are unsinkable, don’t kink your line, come in some sneaky colors and are customizable when wielding a sharpie. I found some in our favorite fly shop in Maine (Rangeley Region Sport Shop) this past June and have been floating them down rivers everyday on the water since.