Put the boat in the water for the first time last night. was running good with no issues, but we pulled the engine hatch to have a look and noticed steam coming from the valve cover vent. Checked the oil and it was clean, not milky at all. The boat was running real cool as well, right around 140. It is a 1996 volvo/ford 302. My first thought was head gasket or cracked head, but the oil looks good. any other ideas? thanks in advance