AIR LOCK IN THE FUEL MIXING COLUMN :
Leakage of FO through oil mist chamber in the funnel. At 0600hrs, one morning the duty AB reported that there was lot of oil on the poop deck. On investigation it was found that oil was coning out from the vent flaps of the oil mist chamber in the tunnel. There was a lot of confusion as that much amount of oil is not supposed to reach the oil mist chamber. Finally it was found that there was a lot of moisture content in the FO which led to a vapor lock in the mixing column. This prevented the return oil from the engine from telling back into the mixing column. This rose up through the vent of the mixing column of had leaked out of the oil rust chamber the tanks were drained of water & FO temperature reduced the vessel could proceed without any further incident.