The only Craftsman brand I had heard of is the tool line sold at Sears. Found the website for Craftsman Marine engine
in the Netherlands
. Their website says they use Mitsubishi blocks that are marinized for the marine
diesels they sell.
This is very common and most Perkins
and many other marine engines are based on the Mitsubishi blocks as well so the quality of the marine parts
added to the basic block will be the main factor. Things like the manifolds, raw water
pumps, coolers, etc.