Monday, September 29, 2014

Wild Phosphorescence -- Ko Phaluai Thailand (September 2014)

Pinnacle Beach, Ko Phaluai
While anchored in four meters of water in a bay on the north of a small Thai island (Ko Phaluai -- lat: 9.550345; long: 99.69351) the other night (28/29 Sept., 2014), I woke up around 1:00 AM to find the boat rocking a little bit, so I went out to check the direction of the wind. Well, there wasn’t any wind to speak of -- the boat was just moving a little, perhaps due to refracted swell (although it worth noting that we had not noticed any swell the previous day and conditions had been calm, so perhaps the movement was due to other reasons). But when I stuck my head out the hatch, I saw long lines of phosphorescence pulsing into the bay. This was definitely something we all had to see, so I woke up Michelle and the kids and we were soon on the foredeck watching a most amazing and mysterious light show.

The pulsing lines or waves were hundreds of meters long (as far as we could see), widely spaced, and maybe 8 meters wide, moving rapidly at a rate of about 3 pulses per second. These slightly curved waves of light were moderately bright and  "clean" -- that is, without disruptions or anomalies, all the same width, evenly spaced, all with the same uniform, undifferentiated, moderate level of phosphorescent glow. The entire effect was incredibly geometrical. Within the waves (and around them) we could also see an abundance of more “conventional” phosphorescence -- intense isolated flashes of green from individual organisms caused by agitation through wavelets and darting fish.

Phosphorescent pulses were emanating from a couple of points within the bay as well, not far from the boat.  They seemed to spin out like scythes from these points -- not points, really, but central areas that were perhaps 4 meters across.  Whenever pulses from different sources met, they flashed together and the train of pulses stopped. That is to say, the pulsing patterns never overlapped or extended beyond the line of contact with other pulsing patterns. It was as if their energies cancelled each other out. Meanwhile, the whole arrangement of pulsing light was slowly moving and shifting the entire time.

Then, around 2:00 AM -- we had been watching for approximately one hour -- the display abruptly ceased; the bay went dark first, while beyond the bay an indistinct glow persisted for a few minutes longer.

It is worth pointing out that we had noticed earlier that the water was very phosphorescently charged, so to speak.

Many years ago we saw something similar while sailing near Hawaii. In that case, we didn’t see waves or pulses of light but rather large (many meters across) sharply delineated angular patches of flashing phosphorescent that lit up the ocean surface.

These large patterned displays of phosphorescence seem almost other worldly. They are impossible for me to comprehend and very difficult describe.

Update:check out the following article "Phosphorescent Wheels: Fact or Fiction" by Peter Herring and Paul Horsman, which examines other accounts of such phenomena (thanks Nancy).


  1. Wow, sounds magical, do you have any video? Haven't seen much phosphorescence -- murky plankton blooms float our boats up here in the north -- but we did lose our torches on a night dive in Egypt once, and I found hubby by the phosphorescence -- as he moved, he sparkled, deep down in the black.

  2. I tried to make a video with a GoPro, but it was too dark. Nice when your love glows like that.

  3. Maybe you could place a camera at the top of your mast and record all night. Sounds awesome!