Vessel Quotas and Operating Requirements Vessel Quotas and ...

• 100% of the vessel wake energy is directed at the shore.
• Wind duration for a storm event is set at 1 hour.
A design boat wake was chosen to represent every vessel wake because reliable statistical information
about each particular class of vessels wakes is not available and the vessel wake attenuation through the
water has a significant effect on its energy at the shore site. The 1-foot design wake is conservative and
biased towards showing an affect on the shoreline. The wind duration for wind-induced waves is
conservative as storms typically last longer than 1-hour.
4.4.3 Site Selection for Analysis
Energy levels were generated at 22 study areas (see Figure 9). Details of the selected sites are shown in
Attachment “Areas identified for detailed study”. These areas were selected by analyzing vessel track
information as provided above.
An energy index value (N value) was generated for each of the 22 sites, and the sites were divided into
the following categories to compare the ability of vessel-generated waves against natural conditions. This
does not consider the substrate material so it is not the effects analysis.
• High – if the energy of the vessel waves is of the same order of magnitude as the wind waves
(1/1). This means that all the vessel wake energy over the year has the same amount or more
energy as natural background conditions and is highly likely to change (erode) the coastline.
• Moderate – if the energy of the vessel waves is one-tenth of the energy of the wind waves. This
means that all the vessel wake energy over the year has one-tenth (1/10) the amount of energy as
a natural background conditions and is moderately likely to change (erode) the coastline.
• Minor – if the energy of the vessel waves is one-hundredth of the energy of the wind waves. This
means that all the vessel wake energy over the year has one-hundredth (1/100) the amount of
energy as a natural background conditions and has a low likelihood of changing (eroding) the
coastline.
• Negligible – if the energy of the vessel waves in one-thousandth of the energy of the wind waves.
This means that all the vessel wake energy over the year has one-thousandth (1/1000) the amount
of energy as a natural background conditions and is highly unlikely to change (erode) the
coastline.
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