The ramp is a bit of an adventure, but manageable. Parking is pretty limited, however, so hope that there aren't a lot of other people with the same idea =)
I don't believe there's a size restriction, but there are some local rules about wake etc.
http://lakeboon.com/rules.htm. No idea how enforcement is, but it seems like mostly a non-issue as long as you use common sense.
You can find the ramp at 525 Sudbury Road. Google maps actually has a street view of it.