Last weekend we visited Ian in Cardiff then on Saturday I travelled on to Cornwall, stayed one night then back home via Cardiff.
Here is my location history ;

In Cornwall a few of us visited a mine shaft, tossed a few rocks down. About 4 seconds to the water. So given that 0.5 x gravity x time squared, it’s about 76m deep.
And also talked about putting an electric speedo onto the land rover to run via the Arduino.
Testing it on the lath;