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Krabi, Thailand’s Blue Bioluminescent Plankton in 2024

[Page Updated 4 March 2024]

This glowing effect in the water at night is a phenomenon that occurs all over the world, but especially in warm water areas. In Florida, we had it around Clearwater, and Tampa as I fished at night from bridges. When We dragged bait through the water, or when fast fish like mahi-mahi ripped through the water they left eery blue-green s-shaped curvy trails.

Here in Krabi, Thailand, there are several places you can go to see the glowing neon-blue plankton lights. Ideally, you’ll be in an area away from the mainland where the water is clear and there have been no storms for a few days. The water should be calm and clear for the best effect. A very dark place is also crucial for the best viewing!

Where Is the Best Place in Krabi to See the Water Glow Blue?

You can come to Krabi, Thailand, and see this glowing plankton for yourself! If you do it on your own, you will have to be a bit lucky as it doesn’t happen every night. Pay attention to the following tips and you’ll have the best chance of experiencing this once-in-a-lifetime experience of swimming in or just walking through bioluminescent plankton in a blue-green blur!

One of the best places in Krabi to see bioluminescent plankton in Krabi, Thailand is at Railay Beach West. The west side of Railay has some areas of caves by Phra Nang cave and this is a good spot to see the glowing plankton.

Another option is taking a night boat tour that includes a stop at Ko Hong, Ko Poda, or one of the other islands close to Railay or Ko Phi Phi where you have a good chance of seeing this glow.

Remember, there is not 100% chance you’ll see this amazing effect. There are some factors that affect your ability to see it. Time of year. Time of night. The phase of the moon. Water temperature. Currents. Clarity of water. All of these affect your chances.

What Time of Year Can You See Bioluminescent Plankton in Thailand?

Blue glowing bioluminscent plankton at Railay Beach in Southern Thailand.
Sometimes the blue glow effect is very bright just with wave-action.

Coming to Railay Beach, Krabi during the high season (November to April or May) can increase your chances of seeing the plankton. Going on a clear, moonless night is highly recommended.

The bioluminescent plankton are easier to see during the time just before, during, and just after the start of the new moon because it’s darkest. So, the best times of 2023 will be during November and December of 2023, but any time around a new moon can produce the awesome result you’re looking for!

New Moon Dates for Blue Plankton in 2023

Come 1-2 days before, during, or 1-2 days after the new moon phase and you will have the best chances of seeing the plankton glowing blue in the water around you.

  • January 21, 2023 (come 19-23rd)
  • February 20, 2023 (come 18-22nd)
  • March 21, 2023 (come 19-23rd)
  • April 20, 2023 (come 18-22nd)
  • May 19, 2023 (come 17-21st)
  • June 18, 2023 (come 16-20th)
  • July 17, 2023 (come 15-19th)
  • August 16, 2023 (come 14-18th)
  • September 14, 2023 (come 12-16th)
  • October 14, 2023 (come 12-16th)
  • November 13, 2023 (come 11-15th)
  • December 12, 2023 (come 10-14th)

New Moon Dates and Best Bioluminescence in 2024

Again, it’s best to come during the dark nights of the month when the moon is not shining strongly. If you come during the days listed, you will have the best opportunity to see the blue plankton in all its glory!

  • January 11 (come 1 – 22nd)
  • February 9 (come 1 – 22nd)
  • March 10 (come 1 – 22nd)
  • April 8 (come end of March – April 19th)
  • May 7 (come end of April – May 18th)
  • June 6 (come end of May – June 19th)
  • July 5 (come end of June to July 16th)
  • August 4 (come 24 July – August 15th)
  • September 2 (come August 22 – September 13th)
  • October 2 (come September 22 – October 13th)
  • November 1 (come October 21 – November 12th)
  • November 30 (come November 20 – December 10)
  • Dec 30 (come December 19 – January 11)

Does rain help or hurt your chances of seeing the glowing plankton?

Rain can cloud the water and hurt your chances of seeing the bioluminescence very clearly. When there is more dirt in the water it can hinder your view of the glowing plankton. It’s best to go in water that is very clear and undisturbed by streams and rivers flowing into the ocean. If the water is clear, then after a rain can be a great time to go!

See Testimonials of others who have joined our Field Trips >

How do I take photos of bioluminescence with my phone?

Start taking photos of the bioluminescence by using a high ISO setting like 400 or 800, even higher if you can on your camera with a wide lens. Choose a wide aperture of f/2.8, 2.0, 1.8 (or as low as you can go) to allow as much glowing light to come through and hit the sensor as possible. Try photos and videos.

You can move your hands through the water to trigger the glow. You can also take photos while waves are coming in and hitting you or someone standing in the water for the best effect.

Our Guide to Taking Photos of Blue Plankton with iPhone or Camera >

What is bioluminescent plankton?

Bioluminescent plankton (bioluminescent phytoplankton), are microorganisms that can emit light through a chemical reaction within their cells as a response to a threat, like hitting something in the water, or something moving through the water.

These tiny organisms are found in both freshwater and marine environments.

Photophores inside the plankton create a chemical reaction that combines with oxygen to produce the eery blue-green glowing light we see with this plankton in the sea. Luciferin, oxygen, and luciferase all combine to create the neon-blue glowing effect.

Bioluminescent plankton causes a blurry light to be seen in the water at the beaches in Krabi at night during dark nights. When these plankton are disturbed by movement in the water, even a breaking wave, they emit a sparkling display of light that looks surreal for people close by or in the water.

Other areas of the world outside of Thailand that have these magical displays include Puerto Rico, Hawaii, the Maldives, South Carolina, and Florida (plus many more!).

Tips for Seeing More Blue Plankton in Krabi

  • Go on a Blue Plankton Tour on a new moon, when the sky is darkest.
  • Choose a dark spot, away from light pollution. Railay Beach is not that dark in most places.
  • Be patient. It may take a few minutes for your eyes to adjust to the darkness and to see the plankton.
  • Move around slowly and gently. The plankton are more likely to glow if they are not disturbed before you start moving around. Get ready for photos right away, don’t wait. They may be the brightest blue when you first disturb them.
  • Avoid using flash photography. You cannot get good photos with a flash. This can damage the plankton and make them less likely to glow.
  • Take many photos! Use a small handheld light to your face to get you in the photo and keep the water dark so you can really see the blue of the creatures.

Timing Can Be Key for Seeing More Plankton

A couple of factors are important for whether or not the blue plankton is present and visible.

  1. Moon Phase – The darker the night, the better. That means going a few days before or after a new moon can offer the best visibility for the plankton. A full moon is beautiful but not ideal for plankton gazing, as the extra light can drown out the glow.
  2. Tides – While the effect of tides on bioluminescent plankton isn’t as straightforward, some people suggest that higher tides can bring in more plankton. That said, it seems to vary from place to place, so local knowledge is golden here. (Let us know if you want to go with us – we know. Form here > )
  3. Seasons – In tropical areas like Krabi, the plankton are often most active during the hot months, although they can be present year-round. However, this could vary, so checking with us or local guides can give you a better idea.
  4. Weather – After a good rain, you may find more plankton. This is possible because rain can wash nutrients into the sea, providing more “food” for the plankton.

Remember to be as still as possible once you’re in the water to let the plankton accumulate around you, making their glow more visible when you do decide to move around. If you’re too excited and splash around a lot, you’ll probably disperse them, making the glow less intense.

I hope this information is helpful. Have a great time in Krabi!

Where is the absolute best place in THAILAND to see the glowing blue plankton?

How to Take Photos to Capture Bioluminescence?

Krabi Attractions >