I've been posting a lot of little projects lately in anticipation for a brew day this weekend (See Quickie Temp Controller and Quickie Mill Funnel ), and this is looking to be the last of the ones I consider possibly interesting.
Since I'm able to see into my kettle during the boil, and I didn't want to bother with a sight glass, this was my solution. It's aluminum and detachable. The top of the tab marks gallon and the bottom of the tab marks half gallon.
nice.... so you have to remember what the top one is and count down to where you are?
I did something similar in my keggles, I took the old spear and scored some rings on it with a pipe cutter to mark the gallons so I just dunk it and pull it out and count the rings to where the water line is.