1976 Merc 200 20HP leak?

[Merc...]

I just change the lower gear lube in my Merc 20HP, after I attached water source and ran it 10 minutes working the gear forward and reverse. I then notices seepage above flush hole? Can anyone tell me what and where this fluid is coming from? Photo here http://www.myhostedpics.com/images/skeeter/photo.jpg

Sorry I think I may have posted to wrong area my bad........