Reply To: AQWA LINE: wrong angle of the principle axes of the cut water plane area

[K. H.]

Thank you for the clarification. I indeed used the equations below from the manual to calculate the hydrostatic stiffness myself. And something goes wrong in the AQWA calculation as it gives the wrong angle of the principal axes of the cut water plane area, that should be 0 and not 90. This results in the Iyy having the value the Ixx should have. Also, it calculates a wrong Ixx, which is about 100 times too small. This results in wrong GM values and wrong hydrostatic stiffness.  

The horizontal positions of the COG and COB coincide. Is there another reason or setting that I might have overlooked that could cause this error? My COG is lower than the COB by the way.