There are few things more recognisable about Mallorca than its sea.
On a calm summer day, the water can range from deep Mediterranean blue to almost impossibly bright turquoise. But why does it look so clear and colourful?
The answer is a combination of sunlight, the water itself, the seabed and the marine life beneath the surface.
Mallorca's unusually clear water
The Balearic Sea is relatively low in nutrients, a condition known as oligotrophic. This means there is generally less biological material suspended in the water than in more nutrient-rich seas.
The result is water that can be exceptionally clear, allowing sunlight to penetrate much further beneath the surface.
And that is important because the clearer the water, the more easily we can see the effects of light and the seabed below.
Why blue becomes turquoise
Sunlight contains all the colours we can see. As it travels through seawater, reds, oranges and yellows are absorbed more quickly, while blue light penetrates further and is scattered back towards our eyes. That is why deeper, clear water tends to appear blue.
But around Mallorca’s beaches, much of the water is shallow. Here, sunlight can reach the seabed and reflect back through the water. A pale sandy or rocky bottom can produce the bright turquoise colour seen around many of the island’s coves.
So when you see that classic Mallorca turquoise, you’re partly looking at the seabed through clear water.
Then there's Posidonia
There is another important part of the picture beneath the surface: Posidonia oceanica.
The Mediterranean seagrass forms extensive underwater meadows around Mallorca and the wider Balearic Islands. These meadows help stabilise the seabed and reduce the movement of sediment, contributing to the health and clarity of coastal waters. It would be too simple to say that Posidonia is what makes Mallorca’s sea blue. The colour comes from several factors working together.
But there is an interesting relationship: Posidonia needs clear water to receive enough sunlight, while healthy meadows help keep the seabed stable.
Why can the sea look completely different from one day to the next?
Wind and waves can stir up sediment, while rain can carry material from the land towards the coast. Particles suspended in the water can make it appear greener, darker or less transparent. Even the position of the sun and the angle at which light enters the water can alter how the sea appears.
That’s why a beach that looks almost Caribbean on a calm morning can look completely different after a windy afternoon.
Five Northern Mallorca beaches with exceptionally clear water
If all this talk of light, seabeds and Posidonia has made you want to get in the water, there are plenty of places around the island where you can see the effect for yourself.
Five worth putting on your list are:
- Cala Clara, Cala Sant Vicenç — its name itself refers to the clear colour of its water, and the official tourism site describes the area as having transparent Balearic waters.
- Cala Molins, Cala Sant Vicenç — its sandy and rocky seabed is covered by transparent water that takes on emerald tones in the sunlight.
- Cala Murta, Formentor — a secluded cove with crystal-clear water and calm conditions suitable for swimming and diving.
- Cala Figuera, Formentor — the official tourism site highlights its seabed for snorkelling and its Posidonia meadows and marine life.
- Cala Barques, Cala Sant Vicenç — its clean water and sandy beach make it a good example of the clearer coastal waters found around the Pollença area.
We’ve also put together a guide to some of Northern Mallorca’s best-kept beaches, including all five of these spots, if you want to explore further. North Mallorca’s Best-Kept Secrets – Beaches Off the Beaten Path
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