Countless pieces of equipment that once served as a means of transportation for people or goods, as weapons of war or for marine exploration, now lie in the almost absolute silence of the seabed. A ship’s useful life, however, does not necessarily end when it sinks. Despite the curiosity that shipwrecks spark in us, it is the frequent inaccessibility that typically characterises them, either because of the great depths at which they are found, their restrictive access for military or security reasons, or simply because of the tremendous logistics and costs involved in exploring them. Millions of shipwrecks are scattered across the world’s oceans, from sunken World War II destroyers, to colonial Spanish galleons and small abandoned dinghies. The reasons for sinking vary and can include storms, navigational errors, warfare, accidents, and natural disasters. Some of them, however, have been sunk intentionally. And while some of these are well-documented and explored, others may lie in remote or deep-sea locations, still waiting to be discovered.

Fortunately, some shipwrecks can be explored simply by using diving equipment, which makes them accessible to almost everyone. Generally, all it takes is some specific dive training. Diving on a sunken wreck can be a fascinating experience. A mixture of emotions runs through the divers who do it. They feel like marine explorers discovering an unknown world full of mysteries or like archaeologists on a journey to see something long-abandoned and considered lost forever.

Shipwreck diving options can be found around the world: the Truk Lagoon in Micronesia, the coast of the Egyptian Rea Sea, the islands of Malta or the Florida Keys are just a few famous examples of places where shipwrecks are popular among divers, but there are many more across the globe, each with its own unique history and underwater landscapes. In these places, they play a critical role in the diving industry, attracting tourists every year.

Sometime in the ‘70s, several countries decided to intentionally start sinking obsolete vessels to attract tourists and to create artificial reefs that would attract fishes to the area. “The installation of these structures creates new homes for a variety of marine life,” states Avery Paxton, a researcher with the National Oceanic and Atmospheric Administration’s (NOAA) National Centers for Coastal Ocean Science, who studies the ecology of artificial reefs. According to NOAA, planned manmade reefs may provide local economic benefits because they attract fish to a known location and are therefore popular attractions for commercial and recreational fishermen, divers, and snorkellers.

Portugal, with a past closely linked to maritime voyages, discoveries, and exploration, but also an agent with great representation on the international maritime route to this day, has a large number and variety of shipwrecks from north to south. Some can also be found near the islands of the Azores and Madeira. Some of them have virtually disappeared through time, ‘digested’ by the marine ecosystem, but others preserve their skeleton practically intact, presenting themselves as impressive structures and invariably an oasis of marine life.

The country, therefore, presents itself as a real sanctuary of shipwrecks, whether from a historical, exploratory, or recreational perspective. And the international diving community has already realised this, with more and more divers flying to this corner of Europe to explore, study, catalogue, and photograph them.

Portugal is at the forefront when it comes to creating artificial reefs by using shipwrecks too. As an example, the largest artificial reef in Europe, consisting of four navy vessels, is located off Portimão, Algarve. Sitting at 30 metres depth, although reachable from 16 metres or shallower, the reef is accessible to scuba divers of all levels who wish to explore and experience wreck diving.

Sinking a ship intentionally for recreational diving purposes is a complex and regulated process. It involves thorough planning, adherence to environmental regulations, and coordination with relevant authorities. While it may sound like an exciting idea, it’s crucial to prioritise safety, environmental considerations, and compliance with local laws. The ‘Ocean Revival’ name given to the artificial reef off Portimão, implicated many years of planning and a ton of bureaucracy, but also a considerable effort in the preparation and cleaning of the ships to make them diveable.

Gonçalo Calado, Professor of Ecology and Marine Biology at Lusófona University, in Lisbon, followed the project from the very beginning. “At the time (2010), there was no specific legislation on environmental impact, so an environmental impact analysis was carried out,” he said.

“The entire ship was washed, degreased and the plastics, coatings and wiring, oils and fuels were removed. As regards to diver safety, all sharp edges or parts that could interfere with the divers’ progress were removed and at all time passages are open (when a diver sees an exit beyond the passage they entered),” highlights the researcher, who is also a dive instructor.

In 2012, the first two vessels were sunk, followed by two more in 2013. Since then, thousands of divers have had the opportunity to explore the wrecks, to learn about the history of each of the ships, but also to witness the abundance of marine life that has colonised the reef in the meantime. “In all cases in Portugal, a monitoring programme has been designed to track the structuring of the communities that have settled/associated with the new reef. This programme is particularly important for monitoring non-indigenous species,” Calado concludes.

Another example of great success is located in the island of Porto Santo, in Madeira. The island, located 50 miles northeast of Madeira, can be accessed from Funchal by boat in approximately 2.5 hours or by plane in no more than 30 minutes. Renowned for its stunning nine-kilometre-long golden sandy beach along its south coast, the island features an arid climate characterised by minimal precipitation and a barren landscape. Despite the aridity, the surrounding waters maintain a relatively warm temperature and crystal-clear clarity throughout the year. Covering a mere 42 square kilometres, equivalent to the size of San Francisco city, the island boasts several hotel resorts lining its shoreline. Additionally, it is a favoured destination among the aristocratic class in Madeira, with numerous families owning summer houses on the island.

In October 2000, ten years before the Ocean Revival was an idea, Porto Santo led the way in the creation of artificial reefs in Portugal. ‘Madeirense’ became the first shipwreck to be intentionally converted into an artificial reef in Portugal. The Portuguese cargo ship, built in 1962, initially had capacity for 12 passengers and was designed to transport bananas from the island of Madeira to Portugal’s mainland. In the early 1990s, it was modified to allow it to carry more passengers, and it began to make the Funchal-Porto Santo connection, playing a critical role in supplying that island. Progress and technological development would make it obsolete, hence the choice for sinking.

More than 20 years later, ‘Madeirense’ is one of the most popular dive sites in Portugal. According to Emanuel Almada, diving instructor at Porto Santo Sub, one of the three diving companies operating in Porto Santo, “the favourable weather conditions and clear waters that characterize this island, combined with the fact that the place of sinking is sheltered from wind and current, and located just a few minutes by boat from the Porto Santo marina, make it an all-year-round dive spot”.

Diving in the ‘Madeirense’ is a truly fascinating experience. The descent is a plunge into the immense blue, but with good visibility, just a few metres below the surface, divers can see a dark shadow that becomes more distinct as the descent continues. Reaching 15 metres, the wreck is revealed almost in its entirety, in an astonishing perspective.

The entire surface of the wreck is now completely covered with colonizing marine organisms such as algae, bryozoans or corals in a unique kaleidoscope of colours, patterns and shapes. It’s also possible to observe various species of crustaceans, mollusks or marine worms roaming the different sections of the ship where waves once hit, passengers sat, crew members operated or bananas were transported. Invariably, divers are greeted by large and inquisitive dusky groupers, the guardians of the wreck. Always curious, these gentle giants approach the visitors as if welcoming them but showing them that this is their home and they will be watching their every move.

One of the greatest spectacles of this dive, however, takes place in the water column surrounding the wreck. Thousands of breams and bogues form shoals that surround the wreck, moving synchronously and confusing the large jacks, sharks, and barracudas that swarm over the shoals in the hope of satisfying their hunger. The seafloor, at approximately 30 metres deep, is sandy, but not less interesting. Stingrays, red mullets and garden eels are common around the wreck and well worth a visit.

The limited air in your dive tank will require you to ascend after a while, but every diver is left with the promise of returning, as there is so much to explore that one dive simply isn’t enough. The tremendous success of the ‘Madeirense’ wreck in the diving community, with tourists coming from all around specifically for this dive, has had a significant impact in the island’s visibility and, consequently, its economy. Aware of this, the local regional government stepped up its commitment to this sector with another sinking in 2016. This time, the vessel chosen was the ‘General Pereira d’Eça’ (CORDECA), an 85m-long navy corvette, built in 1970. The sinking site is approximately two miles from the ‘Madeirense’, in the bay of Porto Santo, part of the island’s network of marine protected areas.

Prior to this sinking, just as in the Ocean Revival, a scientific monitoring programme was implemented. “This programme included a multidisciplinary team, and the aim was to monitor the fauna and flora communities present at the designated site before and after the shipwreck, in order to understand the potential impact it would have on these communities,” says Mafalda Freitas, a member of the project team and currently the Regional Director of the Sea. According to a report published in 2018, the initial results indicate that no negative impacts have been detected as a result of the sinking of the corvette, but it states that “it is necessary to continue monitoring it in order to assess the trajectory of convergence with natural habitats and to understand how this will continue over time”.

As for the diving itself, it quickly becomes obvious that it is moving at a fast pace to achieve the same success of its older ‘brother’ ‘Madeirense’, with a noticeable increase in abundance and diversity with each passing year, attracting more and more divers to the island of Porto Santo. The growth of the international diving community opens up promising revenue in places that favour this type of offer, such as Porto Santo. It is essential, however, that these initiatives are always monitored by studies similar to the ones mentioned for CORDECA and Ocean Revival, in order to assess their impact on ecosystems.

After all, we can’t run the risk of losing the biological identity that makes each of these places so unique and special.