yes i remember back in late 70's drilling holes on PI that where over 2ft thick , the auger would be 3/4 deep before breaking through, its been a long time since I've seen anything over 12, miss those days. smelt use to be so thick you could scoop them up through the hole, fishable ice [ min 5" ] was around for 2 1/2 months now we are lucky to get 2 1/2 weeks