No one has mentioned Cetane Value yet.
Just like gasoline has a octane diesel
has a cetane value, the higher the cetane value the lower the temp an engine
can start, less diesel
combustion knock occurs, less engine
deposits occur less smoke fumes and odor
The cetane number an indication of the types of hydrocarbon in the fuel
more parafinnic, less napthalenes, and aromatics.
Depending on the crude blend and the refinery, virgin stocks (ie not catalytically cracked to smaller molecules) will produce the highest cetane number, but will also have the highest pour point (temperature at which the diesel gels).
All diesel at the pump will meet the high speed diesel engine specifications, there are many other grades of diesels (not at pumps) sold for large engines.
So for marine
use don't buy winter diesel (if possible), if you purchase
some poor quality diesel in the third world, do not operate your engine at full power, warm it up well, install new filters, cool it down well, consider adding a cetane improver.