Raising oil level and milky looking

[Austindem]

Ok so I recently bought a 99 Malibu sportster, first 5 times I took it out it ran fine. I ran it for about 45 hours so I went to do a oil change and the oil level was about 6 inches past the good oil level point and very milky. I pulled the oil filter and put new oil in it twice to flush the milky stuff out. I took it out last night and same thing. The left side of the motor all 4 spark plugs have water on them. What could it be? Head gasket? I’m new to boats but it has the indmar 350. Thank you for any responses 

Edited July 4, 2021 by Austindem

[dlb]

You have a cooling system issue.

I would start with your hunch of a blown head gasket.