Here's an interesting article:
http://iopscience.iop.org/article/10.1209/0295-5075/120/30008/meta
Apparently, ocean entropy production hovers around zero, yet rogue waves (considered a negentropic event) still occur.
What does this mean? Well, it means that apparently there's some sort of correlation between the production of entropy and negentropy!
The 2nd Law of Thermodynamics states that total entropy (disorder) always increases over time in an isolated system... the system cannot spontaneously increase its order (negentropy) without also decreasing order (entropy) elsewhere in the system. The inverse, apparently, also holds true.
You'll note the researchers state that the entropy of the system (the ocean) doesn't cause rogue waves, it's the entropy of the individual paths of the waves which constructively interfere to create the rogue wave!
How can we exploit this? Well, we're already researching constructive interference as means of achieving overunity. The rogue wave phenomenon is considered random in the ocean because we can't track the trajectory of each individually contributing wave, but in our systems, we can. Thus we can generate negentropic "rogue waves" at will by correlating ambient energy to the energy we're putting into the system (or vice versa).
What are the hallmarks of negentropy? Well, besides an increase of order in the system, it also causes a cooling of the system. Where have we heard of that? In some of the systems we're researching!
Per Bak and Ilya Prigogine both researched self-organizing systems (Prigogine received the 1977 Nobel Prize for his work in this field). They both found that for systems far from equilibrium, self-organization and thus negentropy occurred. This is in apparent violation of the 2nd Law of Thermodynamics, until one considers that the negentropy produced in the system must be offset by an entropy increase of the universe overall.