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Mauritius Underwater Waterfall | The Waterfall Under the Sea

Mauritius Underwater Waterfall | The Waterfall Under the Sea

Who doesn’t love waterfalls? Waterfalls are one of those things you always feel you want to see when you’re in its vicinity. There’s a special sense of wonder we humans get when we do indeed stand at the foot of a waterfall, hearing the thunderous crash of water, Earth’s most abundant element.

Standing at the top of one isn’t any less awe-inspiring. The look down can fill you with a sense of vertigo and possibly dread. It’s all about how nature mesmerizes us, though. So imagine the level to which your mind would be blown if you saw a waterfall happening underwater.

To be more specific, I’m talking about a waterfall under the ocean. And such a thing actually exists! Well, sort of. Let’s take a look at the famous Mauritius Underwater Waterfall in the Indian Ocean.

The Underwater Waterfall is a Major Attraction

When you book any of the many incredible all-inclusive trips to Mauritius, chances are you will be offered an opportunity to visit and witness the spectacle that is the famous underwater waterfall in Mauritius.

Tip: If you want some advice on how to find cheap flights to Mauritius or anywhere in the world, check out my ultimate guide to finding cheap flights.

The incredible phenomenon is caused by the volcanic island’s geological foundations, which are briefly explained below. Full disclosure up front: Although it is referred to as a waterfall, it isn’t technically a waterfall at all. That doesn’t detract from the visually stunning attraction that is certainly a major part of the nation’s major attraction list.

What’s more, you may have the impression from images that it would be extremely dangerous to find yourself in the water by this ‘waterfall in the ocean.’ Rest assured, it is no more dangerous than being closer to the coast on the more shallow peninsula, with the caveat that you might sink a little deeper if ever you did venture towards the waterfall.

There’s no strong current or water flow waiting to drag you down. Assuming you can swim or are on a boat, it’s perfectly safe to be floating above the phenomenon, and the geological nature of the ‘waterfall’ explains why.

What Causes this Underwater Waterfall?

Most of the large land areas on planet Earth were once part of a giant mass and now form various continents. However, some islands were formed independently by volcanic and magma activity pushing up from the sea floor. Mauritius is one such island.

The bit of land that sits above the ocean, forming the island, is only part of the result. This pushing up of volcanic matter created the islands and the immediate plateau around them. These plateaus run off smoothly for a while, but then have a very sharp drop off into the ocean’s depths.

In the case of Mauritius, this surrounding shallow plateau is called the Mascarene Plateau. A few yards off the coast, this plateau simply drops away into the deep ocean. The Mascarene Plateau around Mauritius instantly goes from about 450 feet to over 12,000 feet. This is what happens on the southern side of Mauritius.

This doesn’t only provide visitors with spectacularly unique sights to see. The phenomenon also provides the planet with a somewhat unique biosphere regarding plant and animal life.

A Quick Note on Biodiversity and Volcanic islands

It’s ironic that we usually associate volcanoes with destruction. The truth is that the biodiversity (especially oceanic biodiversity) that appears in the wake of volcanic activity is truly remarkable. Most of the time, these islands also happen to be beautiful, at least after a while! 

It’s true that eruptions cause widespread death in the immediate time frame. But typically we find that corals and other sea life flourish in the ensuing years, ironically, due to the island’s high level of endemism, or endemic species of plants and animals.

The Underwater Waterfall in Mauritius Isn’t the Only One

For the record, such an underwater waterfall can exist wherever volcanic islands are on the edge of such a plateau. Another famous example is The Denmark Strait Cataract, which happens to be the highest (or “deepest”) such waterfall in the world.

The Geological Explanation

It’s worth knowing that this type of geological structure is usually relatively new to the planet. Scientists estimate the Mascarene plateau islands are only between ten and eight million years old, making them some of the newest on the planet.

‘Waterfalls’ like the one in Mauritius occur when an island sits at the edge of such a plateau. However, the Mauritius waterfall is quite unique in that it doesn’t have a particularly strong flow of “just water” from the plateau.

Why is the Underwater Waterfall Unique?

First, let’s in no way detract from how amazing the ‘waterfall’ is. If it looks like a waterfall and acts like a waterfall, we could be forgiven for thinking of it as a waterfall (even if it isn’t). Here is the explanation for why it isn’t technically a waterfall.

A waterfall typically has water moving from the point of elevation to a lower point, dropping off the side of a cliff, mountain, or hill. To some degree, this is partially true of most underwater waterfalls, too. The main difference is that usually, the water movement has to do with varying temperatures and currents. In the case of Mauritius, even this is not entirely the case.

In simple terms, water currents moving across the Mascarene plateau create a movement of sand and sediment that similarly seems to flow into the abyss. As the current and sediment drift beyond the volcanically formed coral reefs and into the deeper sections, it creates an optical illusion of a waterfall, albeit below the surface of the ocean. 

This makes it different even from the waterfall in Denmark. That waterfall is simply colder water moving into warmer water without the added visual element of the sediment and sand creating the spectacle.

Additionally, the Mauritius crevasse is horseshoe-shaped and oddly visually familiar, much like many of the waterfalls found on land.

How Can You See It?

If there’s a caveat to the underwater waterfall, it’s that it can only be seen from the air at a certain angle. Sadly, it’s not really possible to observe when you’re in the ocean itself, whether swimming, paddling, or on a boat.

Your best bet is to take an aerial excursion by way of a plane or similar. You can also windsurf on a good day—and there are many good days in Mauritius.

UNESCO World Heritage Site

The incredible biodiversity and biosphere were mentioned earlier. If the waterfall itself isn’t reason enough to visit this beautiful area, consider that the Le Morne Brabant area (which contains the waterfall and more) is listed as a UNESCO World Heritage site.

There is an additional historical reason for the area being significant in world history. The geography of the area, including the nearby mountains, provided a safe haven for escaping slaves during the era of colonial slavery.

Quick Details: Mauritius Underwater Waterfall FAQs

Here’s a quick roundup of some of the common questions people ask about the underwater waterfall in Mauritius.

Where Can You Find This Underwater Waterfall?

The waterfall is located in the Le Morne Brabant, specifically in the Black River district of Mauritius.

Tip: If you’re in the Black River area, consider a Dolphin Swim and Whale Watching excursion by speedboat. It’s a great way to experience some of that unique ocean life in the area yourself.

How Deep is the Waterfall?

The Mauritius island underwater waterfall drops to around 2.5 miles below the surface of the water from around 450 feet at the lip of the plateau.

When is the Best Time to Visit?

The Mauritius summer peak period runs between October and April, with November to February being the peak. This is probably the best time to enjoy the whole island, as well as a visit to the falls.

How Should You See the Waterfall?

Seaplanes can be chartered in the lagoon, but the best way is to include it as part of an all-inclusive tour of the island. For the record, CNN lists the waterfall at the top of its list of must-see things in Mauritius.

Side note: The Black River Gorges National Park also hosts another famous waterfall, this time more conventional and above water. Known as the Chamarel waterfall, it sits in the nearby rainforest. Why not make a day of it and visit both?

Final Thoughts

It is difficult to describe the brilliant spectacle of the underwater waterfall on Mauritius island. Simply put, the view from the air above is truly unique and unforgettable. Never mind that it is, technically speaking, an optical illusion and not at all a waterfall.

The fact of the matter is that nature has provided something that the planet as a whole can treasure. The bizarre and beautiful sight that is Mauritius’ underwater waterfall should be on the bucket list of anyone visiting an Indian Ocean island. Don’t forget to stop by this handy list of travel tips if you do decide to go.