I saw something similar two or three years ago on the ride out when it was still dark outside. There was a small area where the water and the surface just above the water had a strange light to it....40 miles offshore and at 430 am. I stopped in the area and in the area everything became dimly lit. The water had the same kind of wierd white boat wake look to it. One of the guys I had on the boat that day was a geologist and he told me the same thing about the water being full of natural gas or methane or something. He said that some kind of ions interacting with the static of movement caused the light. That was a couple years back and thats all I can remember. Its good that you got a picture of it because when I tried to describe it to people, I felt like they were looking at me like I was trying to tell them I got abducted by aliens or something.