I have owned a boat of one sort or another every day of my adult life. My background as an engineer means I am well suited to understanding not just what should be done, but why it should be done that way.
I have lived on a sailboat for 20 years and have cruised over 25,000 miles in the last 4 years. I have been the service manager for a charter fleet of over 50 boats from 24 to 60 feet. Catamarans, monohulls, powerboats, trawlers. I have understanding of all of them. There is not a single system on a cruising boat that I have not taken apart, rebuilt, repair, or replaced.
Unlike a specialized mechanic, who may have an excellent in-depth understanding of one system in your boat, I understand how they all work together to keep you safe and comfortable.