With underwater sport gaining in popularity and millions of people worldwide getting a diving licence, the number of neoprene-suited holidaymakers at a popular spot can almost outnumber the fish.

Yet adventurous sportsmen and women may still discover some of the finest areas that the aquatic world has to offer, provided they are prepared to fly several hours by airplane to get there, or else forego a few creature comforts.

Many of the lesser-known areas owe their lack of popularity to their remoteness, a lack of tourist infrastructure or political uncertainty. A good example is Sudan.

Whereas most of Egypt’s reefs and wrecks in the Red Sea to the north have already been inundated with divers, parts of Sudan are still largely untouched by the tourist influx and remain reasonably priced, says Heike Gehrmann of the Nuremberg-based magazine Unterwasser.

The classic route taken by most dive ships goes down south. Among the most famous sunken vessels to be explored are the Umbria, which went down in 1940 and is completely encrusted with marine life, or the Blue Belt, which sank in 1977. Equally fascinating is Jacques Cousteau’s overgrown underwater research centre Precontinent II, which still sits on the seabed. The modest number of visitors to these spots means that those who do venture to these parts have a good chance of seeing large fish such as sharks, says Undine Opitz who runs the firm Drop Off Diving in the town of Alfter near Bonn.

Because of the strong currents, Sudan is only really suitable for experienced diving folk who have logged at least 50 dives. Those who prefer their underwater inhabitants to be smaller and with less pronounced teeth should find what they are looking for in the waters north of Sulawesi in Indonesia. The coral reefs here offer a riot of colour with a wide variety of marine life. They lie in the so-called Coral Triangle where the Pacific and Indians oceans meet. There are more fish and coral species in these parts than anywhere else in the world, says marine biologist Matthias Bergbauer from Berlin.

Thanks to the foresight of authorities who established protected zones in this region at an early stage, the reefs have been left largely intact. This is by no means common in Indonesia where destructive and illegal fishing methods using dynamite and cyanide are still widespread.

Diving spots such as Bunaken Island rank among the world’s best and in the Lembeh Strait, serious underwater photographers will find a plethora of tiny marine subjects. Along with the colourful sea slugs, divers will come across perfectly-camouflaged sea horses and blue-ringed octopus.

On the steep walls of the Bunaken protected marine zone, there are countless Eagle rays, swarms of mackerel or reef sharks. There are some other world-class destinations to be considered as well, such as Palau in the western Pacific or Belize in the Caribbean, some of which are largely unknown to European divers. North American and Japanese tourists do tend to go there in larger numbers though, says Manuela Kirschner from Berlin.

It may seem odd that some of the best places to dive are relatively quiet.

But according to Heike Gehrmann, that is because the sport has changed over the years. “It used to be the case that beginners really threw themselves into the hobby and devoted their entire holidays to diving. These days, a lot of people get a diving certificate while on vacation and go diving when the opportunity presents itself.”