Here on Koh Tarutao, the electricity shuts off promptly at 11 PM. For many people, that is a serious disadvantage of staying in a national park. For us, it is a MAJOR plus. The lack of artificial light, combined with the relatively healthy beach environment makes the spectacle of bioluminescent plankton truly spectacular. But bizarrely, we seem to be the only ones out at midnight snorkeling. Go figure!
If you have never experienced bioluminescent plankton, it looks like blue-green sparks floating in the water. The plankton only seems to light up when there is movement in the water, so it’s quite easy to miss if you are not looking for it. If there are small wavelets, you can sometimes see sparks in the white foam; however, the blue-green is not as noticeable against white as it is against the darkness of the clear water. One good way to see the bioluminescence is to stand knee-deep in the clear water and stir your arms or legs around to stimulate the plankton. An even better method is to go snorkeling. The magical effect underwater is phenomenal.
Unfortunately, it’s extremely difficult to get a good picture of the bioluminescent plankton as it’s only clearly visible in total darkness. To help visualize the effect, I photoshoped the image above. It’s actually quite close to what you would see in reality.