At the present time the shore line is 75 feet Is.ndvard from the 

 end of the breakvrater, as shovm in figure 1 and 2. 'The height of the 

 sand fill is estimated to be 12 feet above mean low crater . i'Vs the 

 original depth of water at the present position of the shore line 

 prior to the construction of the harbor was of the order of -40 feet, 

 the average thickness of sand below mean low water is 20 feet and the 

 average thickness of the entire fill is 32 feets The area filled by 

 sand is a triangle, extending 2000 feet along the shore and 3000 feet 

 inland. The volume of fill, accordingly, is of the order of 3,500,000 

 cubic yards. 



The sand on the beach is coarse, the average diameter is 0,4- to 

 0.6 millimeter (Table 1). The slope of the beach is 9° in front of 

 the noimial storm berm, and 12° in front of the artificial piles of 

 sand near the fixed dredge. (Figure 2), Numerous rock fragments up 

 to 6 inches in diameter, composed of granite, geniss, and porphyry, 

 are washed along the beach by the vraves^ The water deepens rapidly 

 off shore > The waves comiionly are 4 to 6 feet highs The tide has 

 a maximujn rise and fall of 5 feeti 



The area of sand fill ends 2200 feet vrest of the breakwater in a 

 rocky point, composed of coarse-grained granitic rocks, A small rocky 

 mass consisting of granite porphyry, lies 900 feet east of the rocky 

 promontory (Figure 2). A jetty 4-00 feet in length has been built 300 

 feet east of the point, in order to trap sand that might otherwise 

 settle on the beach and build .it forward. This jetty had bean in op- 

 eration for 12 to 18 m.onths prior to November 1951 » Di-iring that time 

 a bench had been built seaiTard 100 or more feet ana up to about i^.erin 

 low water level on the ?/est side of the jetty. The beach above this 

 bench slopes 4°. The average grain size is 195 microns. High tiae 

 level is at the same position on the two sridos of the jetty. In oiiher 

 words, sand that thus far has been trapped west cf this jetty is .nuch 

 finer than sand deposited on the beach east of the jet by. Also, the 

 sand has been laid down largely below mean low water ,, The jetty hence 

 does not seem to be catching much of the material that moves along the 

 shore, especially the coarse sand that forms the major loart of the 

 fill , ' 



The beach along the ocean east of the harbor is 200 to 300 feet 

 wide* It is composed of medium-grained sand, having an average dia- 

 meter of 395 microns. The beach slopes 9" and is encroaching upon the 

 breakwater at a very slow rate, if any. 



A sand island is forming inside the harbor about 1000 feet inland 

 from the end of tte Yirest breakvTater. The beach facing tne sea on this 

 island slopes 5°. The sand is fine grained; the average diameter is 

 190 microns 8 A submerged beach is being built along the inside edge 

 of the breakrrater between the sand island and the end of the breakwater, 

 as is attested by vaves breaking along the breakirater a6 they n;.ove in- 

 land. Rocks up to 6 inches in length are washed along this submerged 

 beach by waves. A small mass of fine sand having a median dir-nioter 

 of 170 microns has accumulated in the northeast corner cf the- outer 

 harbor, The slope of the beach here is 3°. 



26 



