So I just called up the green lake park dept. 1. I had to explain to them what a "boat launch" is, and 2. No one could tell me where it might be, besides "near the water" Jeezus, talk about incompetent.
I have fished GL quite a few times and the site above is easy to park and carry your toon or tube down to the lake. There is a gravel put in right there and close to the island where brown trout lay...
Eric's posted spot (~nw corner) is a good one for access and fish - and if there is wind, this is usually the more sheltered side. That said, if the wind is from a different direction, you can park almost anywhere on the road(s) around the lake and walk 50' to put your tube in.
Damn, Can't make this one! Maybe next time. I didn't even know there were fish still in GL! I still need to pick up some kind of inflatable fishing vessel too...Have fun out there, and try to not piss your waders!