Conversation

Dad likes ice fishing. But on the lake we have access to, it's hard to tell when the ice is thick enough to walk on reliably.

So I want to build a device as follows: an upward-facing cone attached to a hollow rod, which is itself attached to the bed of the lake and held perpendicular. Under the cone is a depth gauge; the cone is, in theory, pushed down by the freezing surface water. The hollow rod houses the cable that transmits data from the depth gauge to the surface.