Sorry for the late response - St. Claire is a very fickle lake.
People like to say the fishing is only for a few small fish - but the fish in there get huge - they just don't act like fish in other lakes.
Tried getting info from one of the local fisheries experts (and this lake is one of his studies) and said that even the folks who do good here really cannot understand this lake.
Takes a whole lotta learning of the structure - and even more luck if you want the big boys.
Hope you did well.