why is there a hole in my keel

I'm trying to add an electric bilge pump to my 1980 e-25+ and I ran into an interesting problem. Since the Keel is encapsulated, I was going to drill larger holes than necessary, fill then with epoxy and redrill with the correct size hole for the bilge pump and float switch screws. The idea being to eliminate any possibility of bilge water seeping into the keel (i never have much since its an outboard, but there's always a little from various leaks).

The bilge is pretty tight, so I had to move the manual pump pickup back a few inches to make room. What I found under the pickup was a 2-3" square hole cut out of the glass exposing the lead. The lead has a 1" diameter hole apx. 1-2" deep. I have two main questions;

1.) What is this hole for?
2.) Should I fill it or leave it?

Leaving the hole would make my job easier as filing a few screw holes wouldn't make much difference as long as the large one is exposed, but I'm still concerned about introducing water into the keel.

wondering if the round hole is from a lifting eye from when the keel was lowered into the mold, but I can't figure why it would have a square cut out in the glass over/around it like that - would have thought the eye would be removed and glassed over. I may be completely wrong, but it's my best guess

That was my thought and why I'm scratching my head. My knee jerk reaction is to clean it and fill it with epoxy, but I kind of want to understand what's going on before I do the first thing that comes to mind.

I would clean it up and rough up the surfaces and then fill it up with thickened epoxy. Maybe put a layer of cloth over the top. (Just for the sake of general tidiness - less places for water to sit means less moisture in the boat.)

Loren

Mine had some kind of wooden plugs in those, when it came to me. Well... one of them had a plug and the other was naked. The plug seems to have disappeared now. Not sure why one would ever want to access that?

Could that be a fastening place for a bilge pump intake? My boat was not outfitted with a submersible bilge pump like you have now. Instead it had a "water puppy" pump situated well above the waterline, with a hose and an intake strainer that went down to the bilge. The intake strainer had a little ear with a hole in it where it was supposed to be fastened to something.

(Not a great design because (1) the water puppy did not always prime, and (2) the hose between the strainer and the pump always had water in it when the pump stopped pumping, so that bit of water would drain back down into the bilge.)

Sounds like there isn't a good reason for keeping the hole, so I'm going to fill it up and stick with my original plan for the bilge pump screw holes. Thanks again for the input.