12 SCHEDULE TWO A. Definitions In this Schedule Two, the following words and expressions shall have the following meanings assigned to them except where the context otherwise requires: Approved Wave Gauge means any device approved by Council for the purposes of this Bylaw to measure a Wave Record . IAHR (19 89) means the paper entitled "List of Sea-state Parameters" written by the International Association of Hydraulic Research (IAHR) Working Group on Wave Generation and Analysis and published in the Journal of Waterway, Port, Coastal and Ocean Engineering, American Society of Civil Engineers, Volume 115, Number 8, November 1989, pp 793- 808. Mean Water Level means the average vertical displacement in the Wave Record . Significant Wave Height means the average of the highest one- third of the Wave Heights in a Surface Elevation Record . Surface Elevation Record means the Wave Record relative to the Mean Water Level . Wave Height means the wave height determined from the Surface Elevation Record between any two successive zero down-crossings as defined in IAHR (1989) .