Yanmar SB12 - Where's the zinc?

[Cthoops]

We bought our boat in August, and have zero experience with diesels. We have a Yanmar SB12 and can't see where the zinc is located. I've googled a picture and know what it looks like.

The service manual that we ordered from Torresen is less than helpful. It appears to be a photocopy of a photocopy of a photocopy, so the pictures look like black Rorschach ink blots.

Can anyone give me an idea of where in the heck the zinc is?

Thanks.