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Snorkelling: What’s beneath the surface?

What comes on your mind when you think about snorkelling?
Probably you picture calm, crystal clear water, beautiful coral reefs and colourful fish.
Pretty perfect, but let’s have a better look on what this activity has to offer.

Snorkelling is a simple activity: swimming on the surface while observing the marine life underwater with a relatively little effort.
It is very popular in locations where the coral reef is easily accessible from the shore or by boat and marine life can be simply observed swimming by. But it can get even more interesting than this. In some places around the world, like Tonga and Tahiti (South Pacific Ocean), you can even get to swim with humpback whales
However, let’s take it one step at the time.

Mask on, face down

You are planning your holiday, maybe to escape the cold weather at home. Eventually get on a plane and find yourself walking barefoot on long sandy beaches and there it is: the ocean. Next step is getting yourself the appropriate gear and jump in it to discover a whole new world.

You need a very small amount of equipment: mask, fins and obviously a snorkel. A snorkel is a tube that allows you to breath without lifting your head from the surface. However in the past few years, more and more people decided to use a full-face mask instead. It appears to be easier to breathe without having to hold the snorkel mouthpiece. In colder waters you might also want to wear a wetsuit to keep your body warm for longer. On the other hand, if the sun is strongly shining, you maybe want to wear a rash vest to protect your skin.
At One Ocean we provide properly fitting equipment to make your experience top notch.

Do I have to be a good swimmer?

A snorkelling experience would be more enjoyable if your swimming skills were good. You would feel more comfortable in the water and get the best out of it. But if it’s your first time in the open water and the swimming is a bit shaky, you can have some extra help. To improve your floatability you can easily wear a snorkel vest. Most places will also have local guides, happy to take you for an exploration trip.
As a PADI dive centre, we can take you to the pool before the excursion for a brief but intense course of skin diving. Our staff members will be delighted to help you.
Being able to be so close to the underwater world without having to go deeper is definitely a must do.

Why do we go snorkelling?

Ask this question to a kid and right after to his grandmother. They would probably give the same answer: we go snorkelling to swim with fish!
Some particular ones such as clown fish and blue tang fish became quite well known thanks to animation movies like Finding Nemo or Finding Dory. Therefore, once you get in the water and realize all of that is real, something magical happens. This activity appeals all ages and can be very educational as well.

Unfortunately quite often you will see things that do not belong to the ocean.
We often hear experts talking about the rapid changes in our climate with extremely bad consequences on our seas. What we don’t realize is that a lot of that, comes from our daily routine. The overuse of plastic, for example, is filling our seas with tons of waste every year, in a scary growing number. Snorkelling can be a concrete move to educate on how important is to keep our ocean waste free for a healthier planet.

Get closer, go deeper

Snorkelling often results to be the first step towards a life fulfilled with scuba diving!
When we come back from our trips our guests ask us how they can make it to the next level: jumping into the water with scuba diving gear to get closer to what they could admire from the surface.
Pretty simple: sign up for the PADI Discover Scuba Diving Course , which can lead to a real dive in the ocean right after a short practice in the pool, supervised by a scuba diving instructor. And this is just the beginning...

If Zanzibar is next on your bucket list, check out these amazing locations and let the fun begin.

Coral bleaching comparison

Coral Bleaching

At a time when the human race strives justifiably to recognize diversity and equality amongst ourselves, we can learn some lessons about coexistence from looking at the most diverse of marine ecosystems – coral reefs. Like our own civil rights and liberties, coral reefs also need to be respected, maintained and protected from the effects of human impact. Unfortunately they have suffered from coral bleaching in recent years. We'll tell you why we have to try and stop this process.

What are coral reefs?

Often called the rainforests of the sea, coral reefs are known to contain about 25% of the world's fish species…. Now there is coexistence and diversity for you.


There are 3 main types of reef structures:

  1. Fringing reefs, where they project seaward directly from the shore forming a border
  2. Barrier reefs, where they also form a border but at a greater distance from the shore. They generally have lagoon conditions in between
  3. Atolls, like our own Mnemba atoll, which form when reef grow around a volcanic island. The island subsides completely below sea level while the coral continues to grow upward, forming an atoll.

The formation and growth of coral occurs when free swimming coral larvae attaches itself to submerged rocks, hard surfaces and edges of islands. The coral polyps, when suitably attached, secrete a calcium carbonate forms the skeleton that is the. This base of all coral reefs. On the one hand the skeleton a building block for other corals to grow. On the other hand, it also offers protection to the coral and marine life that reside within and around it. Coral grows best in clear, shallow warm water, they need salt water and sufficient sunlight to survive.

What causes Coral Bleaching?

Two of the main factors that are affecting coral reefs are global warming and pollution. Coral bleaching is happening at an alarming rate threatening the survival of coral ecosystems. Rising sea temperatures due to global warming is one reason why corals bleach. Bleaching happens when corals exposed to extreme stress expel algae, which is a major source of food for the coral. This leaves the coral appearing white and pale and more susceptible to disease. Contrary to belief coral may not completely die when bleached and given the right circumstances can prevail. That said once bleached due to the stress they are under the chance of survival lessens greatly.


How can we prevent it?

Now more than ever we must make a choice to reduce our impact and our added effect to these environmental issues. By reducing our emissions, pollution run-offs into our water sources, use of plastics and overfishing we can not only help revive our ailing reefs but help them grow for future generations of marine life and humans to enjoy and live off.

As well as sustaining one quarter of fish life coral reefs can benefit local communities. Through education and the right practices, responsible tourism is one way in which a community can grow and develop by looking after the coral ecosystem.

At One Ocean, we firmly believe in not only educating our staff but also our clients. We emphasize on the need to follow safe diving and snorkelling practices and standards to help protect and learn about this amazing ecosystem.


One Ocean is partnered with Carbon Tanzania where we help offset our carbon footprint. You as a guest can help by donating to this wonderful cause.

Together we can all make a change.

box fish mercedes benz car

The Mercedes Benz of the fish world… sort of

We have all heard of science taking inspiration from nature. Vehicle designers get inspired by animals to make cars lighter and more efficient. You’re probably thinking of fast and sleek things like swordfish or peregrine falcons. But what about the humble yellow box fish?

Cars designed after box fish?

In 2006 Mercedes Benz revealed its bionic concept car, inspired by the yellow box fish. They thought that its body must have a unique way of being hydrodynamic and self-stabilizing. The box fish moves with strange and impressive agility and apparent ease in its environment.
After development however, engineers discovered that the shape of the fish's body has little to do with its speed.

This means, the car they designed was aerodynamically useless. On top, it was incredibly unstable which makes for quite an unpleasant driving experience. Not to mention the extra drag and resistance resulting in it being very un-economical. For today’s world, where we are trying to "go green", absolutely undesirable.

No car made - but still very cool

So there never was car mass production because of our little yellow friend. However, it actually has other pretty awesome features that the car companies didn’t consider (and that’s probably for a good reason).

When a larger fish threatens this cute little one, it has its own way to react. It will release poisonous proteins from its skin into the surrounding waters. These can actually kill larger fish and scare away any would-be predator. Box fish are of bright yellow colour with black spots which is a type of display called aposematism. It warns any attacker that it is poisonous and could be dangerous, just like the colouration of bees and wasps to show they can cause pain.

So, this little fish has risen pretty high in the corporate world even if it neither knew about it nor succeeded.

We can regularly see the box fish in Zanzibar on our dives. Come join us for some dives to look for the fish that was a car maker’s inspiration.

emperor angelfish juvenile mature

Emperor Angelfish

The Emperor Angelfish (Pomacanthus Imperator) is also known in some parts of the world as the Imperator or Imperial Angelfish. It certainly lives up to its name. With its stunning colors and unconventional personality it surely is one of the most appealing fish in the sea.

Colour transformation

This impressive fish does not only charm everyone it meets but goes through a remarkable change as it reaches maturity. As a juvenile (in the blog's picture), it is a gorgeous looking fish with dark blue, purple, black and white stripes. They are crescent shaped at the front of the body, slowly merging into circles towards the caudal fin. Adults have a light blue background with yellow horizontal stripes across the body behind the pectoral fin. When these fish are around a year old and start to mature, their change in colour begins. This can be a long and slow process for some, taking up to a year in the intermediate stage. For others, depending on food availability and conditions, it is taking a week or less! One thing however is for sure, whichever stage the Imperator is in, it is a striking figure to behold.

Its diet consists of almost anything it can get hold of: Small crustaceans, algae and sponges are its main food sources which means that its mouth has to be very tough. The main ingredient in sponges is silica which would be like us eating pieces of glass for every meal!

Where can we find the emperor angelfish?

Emperor angelfish dwell in reef-associated areas at depths ranging from 1–100 m. Juveniles live alone and inhabit outer lagoon patch reefs or semi-protected exposed channels and reef flats. They tend to hang out at shrimp cleaning stations, feeding off parasites and dead skin of larger fish species. As subadults they move to reef front holes and surge channels. Mature adults are found in caves, in areas of rich coral growth, on clear lagoon, seaward, or channel reefs. Males are territorial and will defend their habitat as well as the females living with them. An angelfish territory can be as large as 10,760 square feet! Which is the same as 1 and a half football pitches! Adults are also known for making a low-frequency “knocking” sound if disturbed or threatened by divers.

So, if you fancy meeting one of these colorful characters get yourself to the Indian Ocean and say hello!