No single system on a boat is more important than the engine, and obviously you’ll want to keep it in tip-top shape with proper maintenance and immediate repairs. But different boats can have very different propulsion systems. You may be interested in outboard motor care, in which case outboard parts, oils, and lubricants will be the main concern. If you have an inboard-powered boat, on the other hand, things like exhaust systems and running gear (all the pieces and parts located below the waterline like struts and shafts) are also likely to warrant your attention. As long as you own your boat the engine will be of paramount concern, so you may also want to consider when it’s time for choosing a marine mechanic and letting the professionals handle the job. Still, there are many basic engine maintenance tasks almost any owner can handle—from corrosion protection, to oil changes, to replacing the zincs. Check out the Boat Maintenance Guide to learn more about some of the jobs you may want to handle on your own and which ones you might decide to leave to a pro.