Engine care is important to keep your boat running smoothly. West Marine stocks oil filters from reliable brands like Sierra, Mercury Marine, Yamaha and others to ensure your engine is running smoothly. Oil filters and oil filter cartridges should be replaced during the oil change process. DIY oil changes require buying the correct oil, oil filter and a functional oil change pump to get the job done. West Marine carries each of these necessities so you'll be ready to do your oil change right and keep your boat running smoothly. Consult your owner's manual or old oil filter in order to determine which West Marine oil filter you need. You can also use our Boat Engine Parts Selector.