I need to install a water line for a new fridge, and would like to know what is on the other side prior to drilling a hole in the floor - is there any tool which would let me place a "marker" or a "beacon" where I intend to drill the hole, then go into my basement, and find where it would end up on the other side if I were to drill there?
edit: I have done my best to measure/map it, unfortunately I don't think it's very accurate since I don't have a good point of reference on both levels. I was hoping for something other than drilling a pilot hole, because there is an air vent that runs in that general area, and I don't want to poke a hole in it