The eigen value maps (plus and minus) can be used to extract directional vectors from the ocean for various uses. Assuming the particle system was capable, for example, the eigenmaps could be used to drive spray emission velocities based on the red and blue values of the maps.
This patch exposes the controls to allow maps to be generated from these eigen value internals.
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.