CONTENTS-Continued 

 FIGURES 



1 Aerial oblique view of Portal Island No. I from northwest 8 



2 Location plan 9 



3 Typical plan of islands II 



4 Typical cross section through island 12 



5 Scour conditions at Island No. 4 16 



6 View of Island White from Long Beach waterfront 21 



7 Location plan 23 



8 Typical sections— armor protection 24 



9 Typical plan view of Island Grissom 25 



10 Typical view of island shorehne sliowing landscaping along top of armor 



protection and buildup of encircUng berm to conceal most of the 



operational activity from the mainland 27 



11 Aerial oblique view of Rincon Island 29 



12 Location plan 30 



13 Plan of Rincon Island 32 



14 Rincon Island sections , 33 



15 View of north side of island showing unusual configuration and good 



condition of armor rock 34 



16 Seal Beach— permanent drilling island 38 



17 Location plan 39 



18 Plan and cross-sectional drawing of filled islands 41 



19 View of steel sheet piUng 42 



20 Aerial view of Sandy Bay breakwater 44 



21 Location plan 46 



22 Typical proposed cross section 46 



23 Looking north along the granite block superstructure of the breakwater 47 



24 Aerial view southeastward towards Cape Henlopen 50 



25 Location plan 51 



26 First rock-mound breakv.ater constructed in the United States— 



the Delaware breakwater 53 



27 Construction stages 53 



28 Delaware Breakwater Harbor 56 



29 Vertical curves of current velocities, Delaware Breakwater Harbor 57 



30 Sections of Delaware Breakwater 58 



31 Delaware Breakwater substructure 59 



