Charlotte Kite, 45, from Denbigh, has been doing dark night photography for just over a year and has tried on at least five occasions to secure a shot of bioluminescence, but was unsuccessful.
That was until she joined Joels on the beach on Saturday with about six other people, after sightings of sparkles in the water the night before.
She said it was by chance and luck they were able to see such a good display.
Kite said the pair arrived at 23:00 BST and could see what she described as splashes of “electric blue lightning” in the water.
“It really is as bright as how it looks in the photos, it’s not a camera trick,” she added.