8. Properly Dispose of Used Oil and Old Engine Filters:
Never dump old oil or filters overboard, no matter how far out at sea you are. After routine engine maintenance, take your used oil and filters ashore for proper disposal. If you're in an area that doesn't have dedicated waste-oil collection, try asking at a local gas station or car dealer for tips on where to dump it, or be prepared to carry it on board until you reach a facility in a larger port.