Looking over the edge of the highest level of the wall, vertically below, can be seen the bedrock on which the Pier is built. This was at about 3.5m above Newlyn Datum. The base of the rock is at around 1.5m. There have been occasions historically when the water level has dropped to 1.5m (5 feet) below that level, and in recent history a level of 1.2m below this has been recorded on a number of occasions.
