portion of the beach. This error is remedied by omitting these grid cell 

 numbers from Line E.4 and the corresponding lengths and depths on Lines E.5 

 and E.6, respectively. 



12. ERROR. DIFFRACTING STRUCTURES OVERLAP. Although GENESIS permits 

 almost arbitrary placement of structures, there are restrictions. One basic 

 restriction is that diffracting structures may not overlap. This means, for 

 example, that it is not possible to place a diffracting groin between the two 

 tips of a detached breakwater. This error will appear if a diffracting groin 

 is specified on Line E.4 in the START file to be located in a cell between the 

 two tips of a detached breakwater as specified on Line G.6. The error is 

 remedied by any of three alternatives: 



a. Replace the diffracting groin with a nondiffracting groin. 



b. Extend the diffracting groin to attach to the detached break- 

 water and at the same time divide the detached breakwater into 

 two detached breakwaters, specified on Lines G.3 and G.6-G.8, 

 each attaching to the tip of the groin, together constituting a 

 T-groin. 



c. Move the diffracting groin so that it will no longer be inside 

 the detached breakwater as specified on Lines E.4 and G.6 in 

 the START file. 



13. ERROR. END X-COORDINATE OF SEAWALL MUST BE GREATER THAN THE START 

 X-COORDINATE. In accordance with the seawall boundary condition, the calcu- 

 lated shoreline location is compared with the corresponding seawall location 

 in each cell within the extent of the seawall from cell number ISWBEG to 

 cell number ISWEND , as specified on Line H.3 in the START file. If ISWBEG 

 is greater than ISWEND , the comparison and corrections would instead be done 

 for grid cells located between ISWEND and the end of the grid. This error 

 message will appear if ISWBEG is greater than ISWEND and is remedied by 

 correcting these numbers on Line H.3. 



14. ERROR FOUND IN DEPIN. FILES DEPTH (AND WAVES) CONTAIN TOO FEW 

 VALUES. If an external wave transformation model is used to calculate the 

 nearshore wave conditions along the nearshore reference line, as specified by 

 setting NWD =1 on Line B.3 in the START file, the corresponding depths and 

 wave information are obtained from the data files DEPTH and WAVES, respec- 

 tively. Following specifications of the total number of calculation cells on 

 Line A. 3 and of the grid cell numbers where the simulation starts and ends on 



C5 



