Motored back to the marina today, about 25 minutes at 2500 rpm on our M18 Universal. Making steady 6 knots, engine temp never exceeded 165. Everything normal. Reduced speed passing entrance to harbor, idled down and motored in for another 5 minutes to the pump out dock. I leave the motor running while pumping out, about 7 minutes and then head to the slip. Having finished the pump out and preparing to leave the dock I see a fair number of what appear to be black oil droplets on top of the water at the stern. Instinct says check the exhaust outflow. Water flow was normal and no trace of any oil there. I look around to see if there is anyone nearby who might have caused this. Don't see anyone. Now wondering if it was from us. Not small droplets, about the size of nickels and quarters and more than I cared to count. Checked the engine oil back at the slip and it was normal. I'm hoping it was from another boat but still concerned because I didn't noticed it approaching the dock and it was quite close to the stern when I finished. Any thoughts or speculation. I don't want to overreact but when there's a small flotilla of oil behind your boat alarms go off.
Steve
Steve