Question about marine diesels
First, let me say that I know VERY little of auto diesels, so what follows is based on my intimate knowledge of my Volvo 2002 (in my boat) and what little I know of my neighbor''s truck.
Compared to auto diesels, marine diesels are a walk in the park. All the systems used to run your auto (which blaze along at 80 mph and thus need some safety concerns, like brakes and power steering) don''t exist on the marine animal. Even systems like A/C are usually completely separate (unless you have a cold-plate fridge system driven by an engine mounted compressor).
So yes, I think if you learn all you need to learn to keep a truck diesel happy, you''ll be in good shape with a marine diesel. There are, of course, differences. But the new stuff will be mostly in cooling and exhaust.
The biggest focus in my life is...
keep your fuel clean, keep your injectors happy.
So, with putting clean fuel in, and keeping a clean tank, and changing fuel filters, then the injectors (the touchy part of an otherwise stalwart system) will be just fine.
Falling short of that, having to rip the thing apart to replace gaskets and valves should be the same (I would think) as a car/truck.
Things (as a cruiser) that I find good to know 1) know what spares you need on a long-distance cruise and 2) know how to install them. Belts and pumps will all break or wear down. Replace them before they break, save yourself some grief at the moment you REALLY need them. Keep two sets of impellers and belts around, one to replace something that needs to replaced, and the second so that after you replace it, Hey!, you''ve got a spare and can still enjoy the cruise without worrying about getting spares.