The eigenvectors in the ocean modifier (plus and minus) can be useful, but are not exposed. Assuming the particle system was capable, for example, the eigenvectors could be used to drive spray emission velocities.
This patch exposes the controls to allow maps to be generated from these eigenvectors. Currently, the values are mapped into a 0-255 range similar to foam.
The names are technical in nature since the terminology is generally understood, but if alternative names are deemed necessary, this is a simple enough change.