Not sure I am convinced of this one, but then again I am not a SOT type. May have more value for someone who is, though I am not so sure about the claim on visibility to other boats.
https://www.westmarine.com/outlet/buy/surfstow--kayak-underwater-lighting-system-2-light-kit--16012866?recordNum=18
A friend has them on his SINK. The underwater view at night was cool. We were paddling the shoreline and saw several large bass.