Wet basalt deepens about two stops past the dry grain. We hold the page at that wet step, never the cream of a sunlit beach.
The grain reads cool — slate, gunmetal, a little blue under cloud — because the shore is ground basalt with magnetite, not burnt wood.
Slate-teal is reserved for the sheen where water meets sand. Used once per view it stays a reflection; used twice it becomes décor.
Archivo and Inter Tight at medium weight, set tight. No serifs, no script — the shore is quiet and the typography agrees with it.