This Data Category is used to input the parameters which are used to define spectra of wind or waves together with their associated current and wind. At present the wind spectra available are OCIN, APIR, NPD, ISO, or User-Defined, and wave spectra available are JONSWAP, Pierson-Moskowitz, Gaussian, or User-Defined, and are uni-directional (see Irregular Wave and Wind in the Aqwa User's Manual for more information concerning wind and wave spectra).

Spectral groups allow the inclusion of multiple wave spectra in a given simulation to model short crested waves.

Applicability to programs in the Aqwa suite is as follows:

Aqwa-Librium - Accepts up to 20 wave spectra or spectral groups, i.e. 20 equilibrium positions are therefore output for each mooring-line combination specified in Data Category 14. This data category may be omitted, i.e. enter NONE for the data category keyword if it is considered that the equilibrium position is not substantially affected by the sea state or if an approximate solution is required. Note that all equilibrium positions are transferred automatically to Aqwa-Fer if requested by the user.

Aqwa-Fer - Accepts up to 20 wave spectra or spectral groups, i.e. 20 spectral response parameters of the model are therefore output for each mooring-line combination specified in Data Category 14.

Aqwa-Drift - Only one wave spectrum or spectral group is permitted, as only one time-history can be executed per run, and each time-history is associated with a single spectrum or spectral group. Additional spectra input are ignored.

Aqwa-Naut - Only one wave spectrum or spectral group is permitted, as only one time-history can be executed per run, and each time-history is associated with a single spectrum or spectral group. Additional spectra input are ignored. The IRRE job option is required and convolution is mandatory.