Figure 12. Coastal Research Amphibious Buggy (.CRAB). 



District for nearshore surveying, the CRAB provides a stable platform in wave 

 heights up to 1.8 meters (6 feet). Top speed is 3 kilometers (2 miles) per 

 hour. Position and elevation are determined by targeting a prism mounted on 

 the CRAB with an electronic survey system which also produces computer compat- 

 ible data. 



Surveying of the beach from the base line to the water line is done using 

 the saiae system but using a person holding a prism at each survey point. 



Pre-1981 surveys used more conventional surveying procedures. Generally, 

 a sea sled or fathometer was used for the nearshore (out to 700 meters) and a 

 fathometer for the offshore (out to 3,000 meters). 



35 



