What can you see inside a steam boiler

[Tōtōchtin]

I have a 59l boiler I had planing on just using as a pot still. Now I want to add a steam option. I was ordering some borosilicate tubes for water level. A friend believes I can see my water level thru my 3 inch sight glass on the top. I feel there would be too thick of vapor in there. He feels it's too hot for it to condense that much.
What's the consensus on this?
Thank you for your time,
Tōtō