Green River Float Question

Ok now been thinking about this for awhile and need some input here... been thinking of floating the green in the yak and doing the Juanita bridge to hwy 18 section... I know drift boats frequent this stretch because most of the river in that stretch is private so there is not a lot of bank access so my main questions though are what should I know before doing something like this and how should I rig the yak up for this?  Do I need a drift anchor?  Has anyone else done or attempted this before if so when should I wait for summer to try this so the flows aren't as high?  Is the green giver just to small to do this with my o.k. t13?