Point buoy 



Mooring buoy, usually for single vessel; see buoys and floats. 



Port 



Place where vessels may discharge or receive cargo. 



Productivity 



Rate of production of offspring, or fixation of solar energy. 



Quay 



Stretch of paved bank or solid artificial landing place parallel to 

 navigable waterway used as loading area. 



Ramp 



A uniformly sloping platform, walkway, or driveway. The ramp commonly 

 seen in the coastal environment is the launching ramp which is a sloping 

 platform for launching small craft. 



Reef 



An offshore chain or ridge of rock or ridge of sand at or near the sur- 

 face of the water. An artificial reef is a similar chain or ridge built 

 up by man to resemble a natural reef. 



Retaining wall 



Wall built to keep bank of earth from sliding or water from flooding; 



see bulkhead. 

 Revetment 



A sloped facing built to protect existing land or newly created embank- 

 ments against erosion by wave action, currents, or weather. Revetments 

 are usually placed parallel to the natural shoreline. 



Ria 



Long, narrow inlet with depth gradually diminishing inward. 



Riprap 



Layer, facing, or protective mound of stones randomly pieced to prevent 

 erosion, scour, or sloughing of structure or embankment; see revetment. 



River datum 



Reference plane for river; each river has a characteristic datum. 



Roadstead (also road) 



A place less enclosed than a harbor where ships may ride at anchor. 



Rubble 



Rough, irregular fragments of broken rock. 



Rubble-mound structure 



Mound of random-shaped and random-placed stones protected with cover 

 layer of stones or specially shaped concrete armor units. 



153 



