Today before getting underway I checked the engine and found the coolant level down and the overflow catch bottle pretty full. I refilled the coolant from the catch bottle. Oil looks good; clear and new looking.

My question is: if the engine was running and coolant overflow spilled it into the catch bottle, shouldn't it have pulled coolant back in when it cooled later? (The overflow tube runs deep into the catch bottle). Will check it again this week.