Swimming with bioluminescent plankton on Koh Rong Samloem, Cambodia
Sometimes when you do something super cool, it gets bigger and more exciting in your memory. It’s a moment that you look back on with immense happiness and nostalgia.
For me, I have this feeling about seeing bioluminescent plankton in Cambodia. It was such a magical experience and it’ll stay with me for a long time.
I enjoyed it so much that I wanted to share my experience with you. In this article, I’ll tell you all about it, as well as a bit of information on how to see bioluminescent plankton too.
The location: Sunset Beach
In November 2023, on our trip through South-East Asia, Lou and I wanted some beach time. After all, we had just been in Vietnam for six weeks. Whilst it’s a lovely country with a lot to offer, one thing it’s not known for is its beaches. We ran out of time to visit Miu Ne, the most popular Vietnamese beach destination in the south. Our stop in Nha Trang, a central coastal city, didn’t really cut it.
Therefore, we booked to visit Koh Rong Samloem, an island in the south of Cambodia. It has a reputation for being a chill relaxing place, which sounded right up our street!
On a whim, we booked to stay at a beach on the west coast of the island: Sunset Beach. It was nightmarish to get there – think an accidental 90 minute hike in full sun across the island – but it paid off in terms of seclusion. There were only four rustic guesthouses on the beach, and it was incredibly quiet.
As Sunset Beach is so quiet, you can see bioluminescent plankton in the water. Although theoretically you can see it in all the sea around Koh Rong Samloem, it’s best observed in super dark conditions, where there aren’t many lights. Less people = better conditions!
The journey: into our kayaks
To give ourselves the best opportunity to see the bioluminescence, we signed up for a kayaking trip. At only $12 (£9) each we figured there would be no harm in it. That way, we could say we kayaked at Sunset Beach, too.
We arrived at Sunset Adventures at 6:15 pm, just after sunset, ready to go. There were ten people in our group (including us). Lou and I got into our shared kayak and the guide pushed us out into the ocean. Once everyone was also out on their kayaks, we began heading across the bay to an area away from lights, where we could witness the bioluminescence.
This isn’t to say we had a good start. Whilst Sunset Beach is normally a very calm bay, and it was that night too, Lou and I had never kayaked on the ocean (or at all really). After five minutes’ paddle, a moderately big wave came along and we lost control of the kayak. Over we went!
On the plus side, at least it gave us some more practice getting in and out of the kayak, which we were grateful for when the group practised it five minutes later.
The scene
After only fifteen minutes of paddling, our guide signalled we could stop. He tied up the kayaks so they’d stay together, and handed out snorkels and masks. We were free to go into the water.
Personally I think it’s a terrifying thought, going to the water at night, when you can’t see the sea or its contents. When I was in the Philippines I saw box jellyfish swimming towards lanterns at night, and since then I’ve always worried something similar could occur.
In this case, I reassured myself by the fact that we’d kayaked to a darker area of the bay, so there wasn’t anything to attract any jellyfish. Besides, in my mind, I figured any jellyfish might prefer the light-emitting plankton, which surely would be much tastier than me.
With the rest of the group getting into the sea and a guide watching us, it was easy to get in. It helped that I was very excited to see the phenomenon for myself.
As soon as I was in the sea, I could see it. Every time there was a ripple, whether it was a splash or kick, the water would light up with little barely perceptible sparks. Every time I moved my hand, the path lit up with sparks, almost like stars.
It felt like magic was happening around me. Whenever I moved and caused sparks to form, I felt like a fairy. Just call me Tinkerbell!
About the magic
Lou and I splashed each other and, as we did, it looked like we were sending little sparks to each other. Each trail would only last less than a second. We both did what has to be the most energetic and least productive version of swimming ever, where we moved our arms and legs about a lot without actually moving, all so we could create more magic.
I find it so fascinating that plankton like this produce light when the water around them moves. It reportedly has come about as a defence mechanism, to confuse potential predators or attract other predators to the area. I’m not sure how it all works, but I will take it; it felt like they were lighting the sea just for us.
Heading back to Sunset Beach
After around twenty minutes in the water, we got back into the kayaks to head back to shore.
Even the trip back was exciting. In part this was because of the adrenaline rush I’d had from being in the water; however, on the other side, it was because our paddles were stirring up the water and causing the water to sparkle as a result.
Back on the beach, we pulled the kayaks in and then were free to leave.
For the rest of my time on Sunset Beach, I kept my eye out for bioluminescent plankton. We didn’t see it to the same degree as on the kayaks, due to the lights being on around the bungalows, but later in the night we could see the occasional sparkle in the waves off the beach.
How to see bioluminescent plankton yourself
Bioluminescent plankton is visible globally. It’s known best for being spotted in tropical countries like Thailand and Cambodia. However, you can see it all across the world; you can even see it in the UK!
On Sunset Beach and in Koh Rong Samloem in general, it’s possible to see bioluminescent plankton in dark water. These conditions are best when it’s a new moon, and where there aren’t that many lights. You’ll find it easier to spot on stretches of the bay where there are few hotels and businesses, or after lights at these places have been turned off.
Something else to consider is the light from moored up boats. We were told that during choppy periods, boats tend to moor up in bays (such as at Sunset Beach), making use of the calmer waters. With them, they’ll bring lights, reducing the chances of seeing bioluminescence.
On Sunset Beach, most resorts switch their lights off around 10 pm, so it’s easiest to see bioluminescence from the beach after this time.
In our case, we took a kayaking trip with Sunset Adventures to observe it properly. The trip cost $12 (£9) per person, lasted one hour, and included the use of a kayak, snorkel and mask. We booked the trip from their office at Sunset Beach.
Conclusion
I loved witnessing bioluminescent plankton off Sunset Beach, on the island of Koh Rong Samloem, Cambodia. It ranks as one of the most magical experiences of my life, and I’ll remember it for a long time.
What was your most magical travel experience? Let me know in the comments!
For more magical moments, check out my story on seeing fireflies in the Philippines
