How valid is Maxsurf Resistance?

As part of my research project this year, i have to use Maxsurf Resistance to test different bow designs. I have to argue the validity of the program itself in regards to comparisons to towing tank data. Although I have searched everywhere, there isn't very much on the validity. The only information I have found is a study on catamarans where towing tank data was compared to results from Maxsurf Resistance and only slight deviations were encountered. If anyone could help that would be great thanks!