I was worried about dealing with my engine too. So I went to a marine diesel course and learned how to do all of the basic maintenance on my engine. It was a 3 day course that demystified a lot. Not cheap but well worth it. You could even do it in a more gold plated way by hiring a diesel mechanic for a day. It would be expensive but he/she could lead you through all of the stuff you would be able to do outside of a boatyard and you can take a thousand pictures while you do it to refer to later. It aint rocket science. It helps amazingly to have done it all once before. Then rent a sat phone so shoreside help can lead you through whatever repair you might need to do that you need help with while you are out there.