last) energy window would fall entirely outside the calculation grid and that 

 wave energy entering through it could not be determined. This error will 

 appear if a breakwater tip is specified in cell number N+l on Line G.6 in 

 the START file and is remedied by either considering the detached breakwater 

 as being semi -infinite by setting IDBN = 1 on Line G.5 in the START file or 

 by specifying the last cell number to be N or less as given on Line G.6 and 

 setting IDB1 = on Line G.4 in the START file. 



10. ERROR. DETACHED BREAKWATER TIP OUTSIDE CALCULATION GRID. GENESIS 

 has the option of performing simulations over a portion of the beach through 

 specification of grid cell numbers other than 1 and N+l where the simul- 

 ation starts and ends. These numbers are entered on Line A. 4 in the START 

 file. To facilitate use of the model, the coordinates of diffracting groins, 

 as entered on Line E.4, and other structures are given in the total coordinate 

 system. In this way the modeler does not have to change the coordinates of 

 the structures as he or she targets one portion of the beach or another for 

 modeling. However, only those structures that appear inside the portion of 

 the beach presently being modeled should be specified. GENESIS transforms the 

 coordinates from the total coordinate system to the local system covering a 

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

 numbers from Line G.6 and the corresponding distances from x-axis and depths 

 on Lines G.7 and G.8, respectively. If the entire detached breakwater is 

 outside the grid, the corresponding transmission coefficient as specified on 

 Line G.9 must also be removed. 



11. ERROR. DIFFRACTING GROIN OUTSIDE CALCULATION GRID. GENESIS has 

 the option of performing simulations over a portion of the beach through 

 specification of grid cell numbers other than 1 and N+l where the simula- 

 tion starts and ends. These numbers are entered on Line A. 4 in the START 

 file. To facilitate use of the model, the coordinates of diffracting groins, 

 as entered on Line E.4, and other structures are given in the total coordinate 

 system. In this way the modeler does not have to change the coordinates of 

 the structures as he or she targets one portion of the beach or another for 

 modeling. However, only those structures that appear inside the portion of 

 the beach being modeled should be specified. GENESIS transforms the coor- 

 dinates from the total coordinate system to the local system covering a 



C4 



