Outer causeway dock 

 Waves from 1 37 deg 



5.61 m (18.4 ft) 



Inner causeway dock 

 Waves from 1 37 deg 



4.02 m (13.2 ft) 



Turning area 

 Waves from 1 82 deg 



3.41 m (11.2 ft) 



Interior channel 

 Waves from 137 deg 



0.4 m (1.3 ft) 



Interior channel 

 Waves from 1 82 deg 



0.4 m (1.3 ft) 



Current patterns and magnitudes obtained for Plan 17 are presented in Plates 48- 

 62 for various waves from 137, 182, and 227 deg. For waves from 137 and 

 182 deg, currents along the shoreline east of the causeway generally moved west- 

 erly, seaward along the structure, and then westerly around the head of the cause- 

 way. Currents west of the causeway moved seaward along the structure. For waves 

 from 227 deg, currents along the shoreline east of the causeway moved easterly and 

 currents adjacent to the east side of the structure moved seaward. Currents west of 

 the causeway also moved seaward along the structure. Maximum velocities were 

 1.07 mps (3.5 fps) adjacent to the west side of the causeway for 12-sec, 5-m 

 (16.4-ft) waves from 137 deg; 0.91 and 2.04 mps (3.0 and 6.7 fps) along the inner 

 and outer causeway docks, respectively, for 12-sec, 5-m (16.4-ft) waves from 

 227 deg; and 0.85 mps (2.8 fps) along the shoreline between the causeway and the 

 existing entrance for 12-sec, 5-m (16.4-ft) waves from 137 and 182 deg. 



The general movement of tracer material for representative waves from 137, 

 182, and 227 deg is shown in Plates 63-65 for Plan 17. Sediment along the 

 shoreline east of the causeway between the proposed and existing entrances 

 generally moved shoreward and then easterly for waves from 227 deg and westerly 

 for waves from 182 and 137 deg. Sediment along the shoreline west of the cause- 

 way moved to the east through the breach for waves from 227 deg. This material 

 split and moved in both directions (east and west) for waves from 182 and 137 deg. 

 Sediment along the west side of the causeway at its outer end moved around the 

 head of the causeway for waves from 227 deg, but for waves from 182 and 137 deg, 

 moved in a clockwise eddy at the outer end of the structure. 



Tracer material was placed west of the causeway along the shoreline for Plan 18 

 and subjected to representative waves from 227 deg. Visual observations revealed 

 that material would move to the east through the breach in the causeway and deposit 

 in a clockwise eddy in the deposition basin. 



Results of wave height experiments for Plan 19 are presented in Table 5 for 

 representative waves from 227, 182, and 137 deg. For 2-m (6.6-ft) wave conditions 

 with the +0.5-m (+1.6-ft) swl, maximum wave heights were as follows: 



Chapter 4 Experiments and Results 



31 



