Do not neglect maintenance on your boat, boat systems, especially your engine. It is every boat-owners responsibility to learn a little bit about all the systems on your boat. Everything on your boat requires regular inspection and maintenance if it is to keep you safe and enjoying the cruise. CPS has a great course on Boat and Engine Maintenance that can get your started. Regarding the engine at the very minimum you should be doing the following: changing the oil and filter (if present) every 100 hours or as specified. Monitoring and changing your fuel filters in a timely manner. If you do not have a vacuum gauge to monitor your fuel system, then this must be done annually.  Know what to do if you get water in your fuel and the motor stops! Having a basic procedure to remove water from your water separator and then bleed the system to the injectors is critical. It would be extremely expensive to have to have a mechanic travel upriver to help you. Belts should be inspected, adjusted and changed as required. You need to be able to do this yourself. I have often suggested the book “Good Old Boat” as a basic resource for the various tasks that every boat owner should have.