Vessel Quotas and Operating Requirements Vessel Quotas and ...

TABLE 5VESSEL WAKE AND WIND WAVE ENERGY COMPARISON AT 2 SITES
Site Vessels Wind Energy
Index (N) 4
Significance
Level
# of Energy Energy
vessel
wakes
Stump Cove 362 112 148,000 0.008 Negligible
(site 20),
Beach A
Lower West
Arm (site 11),
Beach A
6,515 2,014 108,000 0.02 Minor
Wave energy at a site is expressed in units of square feet perpendicular to the shore. However, the actual
energy transfer takes place on the face of the shore, which is the long rectangular area under the breaker
in Figure 8. A steep beach will have a much larger concentration of energy upon its face than a gentler
sloping beach as shown in Figure 8. The range of beach slopes in Glacier Bay proper is approximately
1/10 of one degree to 75 degrees. For the range of beach slopes here, there is a range of between 1 and
600 square feet of beach area influenced by the waves. Thus the concentration of energy on the steepest
beaches is 600 times the concentration of energy on the gentlest beaches for one given wave climate.
TABLE 6POTENTIAL AFFECT ON 22 SITES BY VESSEL WAKES WITH CURRENT QUOTAS.
Site Beach potential 5 Assigned Site Total
potential 6
1 Negligible Negligible
2 Minor Minor
3 Negligible Negligible
4 Minor Minor
5
Minor
Minor
Minor
6 Negligible Negligible
7
8
9
Negligible
Negligible
Negligible
Negligible
Negligible
Negligible
Negligible
Minor
Negligible
Negligible
Minor
10 Negligible Negligible
4 Energy Index (N) is equal to the vessel wake energy divided by the wind wave energy.
5 Each site is divided into one or more beaches. This is due to the different fetches and variations in the shoreline,
which affect the waves that can strike the shore.
6 To be conservative, the highest potential level for a beach is also the total potential.
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