13 Wave Period means the time period between two successive zero down-crossings in the Surface Elevation Record as defined in IAHR (1989). Wave Record means any record of vertical displacement of the sea water surface as a function of time derived from measurements made with an Approved Wave Gauge at any location within th e Defined Area under calm conditions at a standard water depth of 3 metres. B. Maximum Wave Height The Wave Height, H (measured in metres), and the corresponding Wave Period, T (measured in seconds), derived from eac h success ive pair of zero down-crossings in any Surface Elevation Record attributable to the passage of any Vessel to which this Bylaw applies within the Defined Area shall comply with the following equation, namely: H 0.5 4.5 T C. Methods of Assessment 3.04 of this Bylaw to demonstrate that a vessel will comply with the requirements of Clause B and the equation above may include the results of: (a) Accepted and properly calibrated computational or analytical analysis taking account of the specific characteristics of the vessel concerned and the conditions within the Defined Area taking account of shoaling, refraction and diffraction effects; or