The converted-wave azimuth moveout (PS-AMO) operator is a partial-prestack migration operator that transforms converted-wave prestack data from an arbitrary offset and azimuth to equivalent data with a new offset and azimuth position. Two of the main applications for the PS-AMO operator are geometry regularization and data-reduction. I test the PS-AMO operator in a method that not only solves the problem of irregular geometry in 3-D acquisition but also reduces the size of the dataset from a five-dimensional cube into a four-dimensional cube. Application of this method on a portion of the real 3-D OBS dataset from the Alba oil field shows that we can satisfactorily obtain a regularized common-azimuth data cube that honors the physics of converted waves better than conventional methods.