Front diff is milky and never submerged

so I changed the fluids in the front and rear diffs, the back was good but the front was milky. I was in some deep water but nothing over my key. So I know the vent was not submerged. Has anyone else come by this and where else could water Get in? Maybe the driveshaft seal? I also know forsure that the vent is up near the pod.

Thanks