I was at Buckeye Lake today about the time of your posting. It's a nice lake with many places for boaters to stop and enjoy throughout. Fun would pretty much sum it up. Like Lake St. Marys (Grand Lake to some) it's not very deep and if I'm not mistaken it was also man made to supply the canal system years ago. I'm sure others know more about it than I. There was a pretty big amusement park there years ago and I'm told a private Amphicar owner comes and goes from an Island from time to time. There is also a floating bog possibly the biggest one known on the lake. They give tours on it twice a year and there is a lottery selection process to see who can go.
Hope your doing well.
What a funny coincidence that you were at Buckeye lake the day I posted this. It looks as though that area was a rather nice vacation area with a large swimming pool, dance hall and marina area. Like many such areas it appears that those things are gone now but the lake still looks like an interesting place to run an Amphicar, many islands and houses to check out. Like you suggested this lake was another canal reservoir that was hand dug around 1825 so I suppose it, like Grand Lake St. Mary, is quite shallow. The aerial photos on Google Earth have the water looking quite greenish.