I replaced the Zinc before we left and noticed that after only 10 days, I noticed it was corroding. Is this normal?
This is not normal, and it means you have stray current corrosion going on. Galvanic corrosion is normal and that is what the Zinc is for. But noticeable deterioration of a Zinc after 10 days means you have a stray current corrosion problem. I recommend you install a fail-safe galvanic isolator for your boat and find the source of the leak. You can also refer to our article Protecting Your Boat From Galvanic Corrosion for more information.