When I look at the waves within a simulation I like to view the wave heights overlain with wave vectors. The magnitude of the vectors is the WVHT output and the direction the WVDIR output (cartesian convention). A neat way to do this is to use the "Expression" property of a fvg_sheetvec object.
Example:
% create the control object
fvcObj = fvgraphics;
% visualise the wave heights
sheetObj = fvg_sheet(fvcObj,'mymodel.nc','Variables','WVHT');
% create the expression which defines the x-component and then the y-component of your vectors. The x-component must come first
expression{1} = 'WVHT.*cosd(WVDIR)';
expression{2} = 'WVHT.*sind(WVDIR)';
% create the vector object
vecObj = fvg_sheetvec(fvcObj,'mymodel.nc','Expression',expression)