Wave Agitation Criteria for Fishing Harbours in Atlantic Canada

The existing criteria for defining allowable levels of wave agitation in Canadian harbours are outlined in the Guidelines of Harbour Accommodation (Fisheries and Oceans). These criteria were developed based on a previous study which concentrated primarily on recreational harbours. However, it was realized that fishing vessels, when berthed or moored, may be able to tolerate a greater degree of wave agitation than pleasure craft because of the different characteristics and functions of the two types of vessels. Furthermore, fishermen tend to have more liberal tolerance limits to wave agitation than pleasure craft owners, and have more rugged craft. To develop new allowable wave agitation criteria for commercial fishing harbours in Atlantic Canada, a field measurement programme was conducted in selected harbours. The objective was to determine the threshold values at which the wave climate at both the service/offloading area and mooring area creates either dangerous, difficult or unacceptable working conditions. This was determined to be the point at which operations must cease or the vessel had to be removed to a more protected area. Wave measurement gauges were installed at two locations within two study harbours, and a wave rider buoy was used to measure nearshore waves for each harbour site. A procedure was also developed whereby daily field observations were taken and recorded by the harbour master. Particular emphasis was given to the wave climate events which rendered the facilities less than adequate, unsafe or unusable. By correlating the harbour masters field observations with the measured wave data, the threshold values for unacceptable wave agitation were determined, and new wave agitation criteria for fishing harbours recommended.