What is this?

[Alvorada]

So, I am embarrassed to ask, but in the attached photo, what is that? I never noticed it before, but this weekend I had emptied the lazarette and climbed down into it (as I had done many times before) for something else. I looked up and was surprised that in 4 years I had never noticed this. Any help?

 

[woodster]

gps antenna

 

[NiceBeny]

Don't be embarrassed that's how you will learn, spend time going through your whole boat,follow wires to see where they lead, etc