Edgeiness

Its also where all the debris washes up, the tidal flotsam, the litter against the edge of the fence.
I like the idea of flotsam and litter, allows a bit of wrongness, a bit of edgeiness into the discussion.
The edges of  piers are always fascinating, the possibilities of jumping, the edges of different materials touching, colliding, interacting...rust and rot...the stain of time and weather.