Mercury 150 Outboard Lower Unit Question

[Kalsaint]

Good Evening,

I was hoping someone would know what the hole in my lower unit for a 150 Mercury outboard would be? It's located towards the transom of the boat, right above the bulge in the lower unit on the starboard side?

Thank you,

https://imgur.com/a/aBm6njo

 

[Nater Potater]

IIRC, it lets some of the internals drain once the boat is pulled out of the water.

 

[Kalsaint]

Awesome, thank you. She's new to me and my 1st Mercury. I just wanted to make sure I wasn't missing a screw or plug.