First year for Catalyst on Mercruiser Big Block?
 

Trying to figure out what model year the catalysts were added to the big block non-racing engines and the Google search is inconclusive at around 2010. Anybody know for certain when they were introduced?

I was thinking 2010’ish as well.

It's surprisingly hard to get anything definitive from the Web...
But it was an interesting research project...I always wondered how the catalysts were done, pretty damned ingenious!