Thru hull Question

[Chschaus]

Was starting the bottom prep and noticed the thru hull for the galley sink seemed to be cracking away from the hull, I pulled at it and it cracked away and broke off, however it seems to be just a flat ring to level the fitting with the hull. I plan on replacing the entire fitting but don't see this piece in the fittings I've looked at online. Is something that changed over the years? I've never changed

 

[Chschaus]

These images are a bit clearer

 

[Loren Beach]

Since the left hand picture (tan color) looks like a casting of the face of the OEM RC Marine thruhull fitting, this might have been filler applied to level the opening. Why they would go to that trouble is a mystery. That's if... my guess is accurate.

 

[Chschaus]

I'm thinking that also Loren, it creates a smooth surface to reduce drag. The fact that there seem to be nothing more than paint holding it in place I'm thinking fairing compound to fill the slight concave of the actual fitting.

 

[gabriel]

Do you have a pic of where it came from (thru hull)?

 

[Chschaus]

I don't, didn't think to take one before I left the marina. I'll take one next time I'm there.

 

[Chschaus]

Turns out it was in fact filler, the fitting was in good shape, re-applied with formula 27 and painted the bottom.
Thanks for the input everyone.