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There’s An Enchanting California Bay That Mysteriously Glows Electric Blue At Night

Imagine gliding across a vast bay, surrounded by water that sparkles with a vibrant blue glow.

This enchanting phenomenon isn’t from a fairy tale – it’s very real and can be witnessed in a unique part of California. 

Here, Mother Nature’s very own light show unfolds in front of your eyes as microscopic creatures light up the water in a display of natural wonder. 

Ready to discover where you can experience this mesmerizing spectacle for yourself? 

Let’s set our sights on the shimmering shores of Tomales Bay.

Tomales Bay

Tomales Bay is located along the coast of Northern California. It separates the Point Reyes Peninsula from the mainland.

This picturesque escape is just an hour and a half drive north of the bustling San Francisco. 

It’s an inlet that stretches on for nearly 15 miles and is framed by rolling hills and scenic landscapes that are characteristic of Marin County. 

Its waters are teeming with life, from oysters and clams to numerous fish species.

One of the most mesmerizing features of Tomales Bay is its bioluminescence which causes it to glow electric blue at night just like a glowstick!

This stunning natural phenomenon occurs due to tiny microorganisms called dinoflagellates, also known as sea sparkle. 

It’s actually a type of plankton!

These microscopic creatures emit a brilliant, glowing light when they’re disturbed by movement in the water. 

This can happen through a variety of ways, such as the movement of kayaks, the paddling of oars or even just the natural motion of the waves.

At certain times of the year, the conditions are just right for these dinoflagellates to flourish and the bay turns into a spectacular, glowing spectacle at night. 

It’s incredible to see in person.

In fact, Tomales Bay has been rated as one of the best places on Earth to experience this unique natural phenomenon!

This is mainly due to the low light in the area which makes conditions perfect for the glowing organisms.

The light emitted can vary in color and typically ranges from electric blue to vibrant green but even yellow and red colors have been recorded.

These bright colors illuminate the water with each disturbance creating a magical sight. 

As kayakers paddle through the bay, their movements stir up this display which creates trails of light that mirror the starry sky above.

It even sometimes makes the fish inside the bay glow bright blue as well!

The glowing waters at Tomales Bay are not just a beautiful sight, they’re an extraordinary example of nature’s magic at work. 

The experience of seeing the water light up around you with sparkling colors really makes you feel connected to the wonders of the natural world.

It’s an unforgettable adventure!

Why Does The Water Glow?

The tiny dinoflagellates produce these bright lights for a few different reasons.

It’s usually to scare away predators, attract prey or to communicate with other microorganisms.

When To Visit

If you’re hoping to see the magical glow of bioluminescence at Tomales Bay in person then timing your visit is key. 

The best time to experience this natural light show is during the warmer months, from July to October, but it is often seen as early as spring.

During this period, the conditions are just right for the dinoflagellates (the tiny organisms that create the bioluminescence) to thrive in the bay’s waters.

Specifically, you’ll want to plan your visit around the new moon phase of the moon cycle if possible. 


Because it’s darker during a new moon and without much moonlight, the bioluminescence becomes even more visible and striking. 

The darkness of the night sky helps the bright blue and green lights under the water stand out which will make your experience even more enchanting.

Cloudy nights are best because it’s even darker!

Also, it’s a good idea to check the weather before you go. 

Calm nights are perfect because too much wind can make kayaking dangerous and so kayaking tours may be canceled.

Remember, while summer and fall are the best times to visit for bioluminescence, Tomales Bay is beautiful year-round. 

So any time you choose to go, you’re sure to enjoy the natural beauty of the area.

How To Visit

Visiting Tomales Bay to see the bioluminescence can be a thrilling adventure and there are a couple of ways you can go about it.

You can either join a guided tour or set out on your own.

Join a Guided Tour

Kevin Lam / Flickr

Many tour companies around Tomales Bay offer guided kayaking tours that are specifically timed to catch the bioluminescence at its best. 

These tours are great for both beginners and experienced kayakers. Expect the tour to last around 2-3 hours.

Some companies which offer these include Blue Waters Kayaking, Napa Valley Paddle and Tomales Bay Expeditions. 

The guides are knowledgeable about the area and can lead you to the best spots for viewing the glowing waters. 

They also provide all the necessary equipment like kayaks, paddles and safety gear so you don’t need to worry about bringing your own. 

Plus, having an expert guide with you means they can share interesting facts about the bay and its unique ecosystem as you paddle through the glowing waters.

They usually depart around sunset meaning you’ll also be treated to stunning views of the sun setting on the horizon.

Go on Your Own

If you’re an experienced kayaker and prefer a bit more adventure, you can choose to explore Tomales Bay on your own. 

To do this, you’ll need to bring or rent your own kayak and safety equipment. 

Try to plan your trip during the new moon for the best chance of seeing the bioluminescence and always keep an eye on the weather. 

Paddling at night requires extra caution so it’s wise to be familiar with the area and kayak with other people.

Whether you go with a tour or on your own, seeing the bioluminescence at Tomales Bay is a mesmerizing experience. 

Just remember to respect the natural habitat to preserve the peaceful environment and ensure that the bay remains a haven for its wildlife.

Know Before You Go

Before you head out to Tomales Bay to see the stunning bioluminescence, here are some important things to keep in mind to ensure your trip goes smoothly.


Parking is available at various points around Tomales Bay and within the Point Reyes National Seashore.

It can fill up quickly though, especially on weekends or during peak visiting times in summer and early fall. 

It’s a good idea to arrive early to secure a spot. Make sure to park in designated areas only to avoid fines.

Many people opt to park at Miller Boat Launch.

How to Get There

Tomales Bay is located in Marin County. 

If you’re coming from San Francisco, drive north on Highway 101 then take the exit toward San Anselmo.

Then follow signs to Sir Francis Drake Boulevard which leads you to the area. 

The drive offers scenic views and takes about an hour and a half.


Facilities like restrooms and picnic areas are available at various points around Tomales Bay, particularly near popular launch spots and beaches. 

However, facilities can be limited in the more secluded areas so it’s a good idea to use the restroom before you arrive and bring any snacks or water you might need.

Opening Times

The bay itself is open to the public at all times but specific parks and launch sites around the bay may have specific opening and closing times. 

Check these times before you plan your trip especially if you aim to be out during the evening to see the bioluminescence.


Always prioritize safety especially when kayaking at night. 

Wear a life jacket, carry a waterproof flashlight and have a whistle for emergencies. All of these are provided for you if you join a tour. 

It’s also smart to let someone know your plans and expected return time.

Environmental Considerations

Remember to respect the natural environment of Tomales Bay by following ‘Leave No Trace’ principles. 

This means packing out all your trash and avoiding disturbing wildlife.

By keeping these tips in mind, you’ll be all set for a safe and enjoyable visit to Tomales Bay!

Sophie Davis

Born and raised in the Bay area of California, Sophie is a California native. She joined our team in 2023 to create travel guides on California.

Learn more about the Traveller's Elixir Team.

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