Marine grade 85-95 weight lower unit oil. Sometimes Walmart carries it in their brand and almost always has the Merc brand at twice the price. You can use auto rear end oil, but it has less corrosion inhibitors added.
Thank you sir. I don't know when the oil was last checked by PO if at all so I figured I ought to check it out. Am planning on really going through the entire boat this winter so if it is low before I go out today then I will jus use the 85-95 I currently have here and change it all then.