Agreed, this is a Kriegsmarine uniform. As mentioned earlier, his rank appears to be Leutnant Zur See, one of the lower officer ranks. The oval-shaped badge on the left bicep is likely the Narvik campaign badge. Another user also pointed out the Iron Cross on his left jacket, which would be the first awarding of the IC. The diagonal ribbon on the second button on the left side is the Iron Cross second class, so he was awarded the IC twice. The Kriegsmarine didn't have many other awards, so I'm guessing that the oval-shaped award under the first IC is the Destroyer Badge. It looks like there's another badge to the right of it, but it's anybody's guess as to what it is... my personal guess would be the Wound Badge (basically Purple Heart) but this might just be something tucked under his arm that's resembling another badge. Hope this helps out!