14 (b) Direct measurements of Wave Height and Wave Period specific to the vessel concerned ; or (c) Combinations of approaches (a) and (b) above. D. Compliance Monitoring For the purposes of compliance monitoring, any Vessel to which this Bylaw applies shall comply with the provisions of Clause B above based on any Surface Elevation Record derived from measurements made with an Approved Wave Gauge at any location within the Defined Area under calm conditions with a water depth in the range 1 to 5 metres. Such measurements shall be made by, or under the supervision of, a competent expert experienced in the measurement of waves. Any site at which compliance monitoring measurements are carried shall, in the opinion of the competent professional, not be significantly influenced by the effects of diffraction. Calm conditions at any measurement point shall be deemed to exist where, immediately prior to and during the time of measurement, the ambient waves caused by wind and other vessels (other than the vessel under evaluation) do not exceed a Significan t Wave Height of 0.05m assessed over a 5 minute duration or more. Any wave height assessed at the measurement site shall be adjusted to determine the Wave Height applicable in the equation in Clause B above at a standard depth of 3 metres by applying shoaling and refraction analysis. This analysis shall be based on the following methods and assumptions: