Bob,
I thoroughly enjoy your posts on the KY board. I made it up to Erie once or twice a year for the last 10 years. It is unreal for walleye and very good for smally's but it is more like an ocean than a lake. I have seen it turn from calm to 5ft waves in 15 minutes. I can't say I have ever seen a pontoon on the lake. I have 19ft deep v and I ferry it to Kellys island when I go. I have never ferryed to Put In Bay so can't help you with the Miller Line. I would think September would be pretty calm but you just never know. If you try it, head for land first storm you see!