Does anyone know what this pipe is for?

[sunshinecoasting]

My 2000 has this pipe in the rear birth on the starboard side, I have no idea if it is a factory fitting or done by the PO and I certainly don't know what purpose it has/had. Click on image to enlarge.

[Cougar]

It's factory standard. You can run cables and wires from the stern through it. The other end is on the starbord side of the motor well / transom.

[Retcoastie]

Correct. In fact, my steering cable goes thru the larger one.

[Tomfoolery]

I can't get over how clean and shiny it is back there.

And I have some wiring running through mine, though my steering and engine control push/pull cables go through the other hole, where yours are.

[DaveC426913]

I have a 2000 as well. My steering and throttle cables run through there.

I'm curious why/howe yours do not. Yours seem to emerge from the engine well.

Can you post a pic of your well from the outside? I'd like to see how your cables connect. Do you find it works well/poorly that way?
Emerging from the stb transom is actually awkward. Not only do the cables get in the way, but they bend at an off angle to attach. When I move the OB up/down, the cables spring back and forth.

[Starscream]

It's to let mosquitoes in at night.

I had to plug mine to stop the invasion. I didn't know what it was for but it was the only place I could find that they could be getting in. After that...peace.