Thru hull identification - ‘84 offshore I/O

[CalvertGrady]

I’m not sure if this is the correct place or not to post this. If it isn’t I apologize. I’ve tried searching everywhere but cannot find an answer for the life of me. I recently bought a 1984 offshore I/O and we cannot figure out what these thru hulls go to. Does anyone know what the front port side thru hull (second picture) and the starboard top thru hull (above waterline) (first picture) are? I’ve attached pictures to make it easier to visualize which ones I’m asking about.

 

[DennisG01]

I have the same boat, but am not near it to 100% double check. However, it's easy enough to figure out. The ones near the water line will be a gravity drain thing - fish box/cooler or floor drain. Just pour some water in the various drains and see where it comes out. The higher drains will a pump-driven drain. Check for nearby things with pumps.

Or, have someone tap on the thru-hull while you move around inside/open thjngs up - the noise will be louder when you're near it.

 

[glacierbaze]

Higher one could be a sink drain. Have someone stick a water hose to the outside, and see where they come out on the inside.