I have a 98 seadoo 951gsx limited. For some reason i am getting a milkey looking water in engine compartment.?

[madmd2020]

I have check all hoses & changed exhaust hose. Repaird leaky vavle on top of exhaust. It only comes in when running on the lake. Can not get it to come in when water hose is connected.
IT takes on about 1/2 the engine compartment while in water for about 1&1/2 hours. Milky of course! Thanks