Mine is just a solar yard light (the kind you stick into the ground next to your sidewalk, in a flower bed, or facing the house. I zip-tie it to the dock facing down at the water. No "zap" to it, but bugs fall in anyway.
Exact same thing I did, I have no power at the pond but picked out several pretty good and bright solar lights that point downward and hung them at the edge of the dock, a few inches above the water and they are swarming with bugs and gnats nearly all nite.
