The methodthat changed marine archaeology.

It all began with a childhood visit to the Vasa museum in Stockholm. Richard and Ingemar Lundgren set the goal: find Mars Makalös. Together with Fredrik Skogh they spent two decades on systematic side scan surveys of the Baltic seabed off Öland — without finding the wreck.

They became technical divers precisely to be able to reach Mars one day. By the time the wreck was found in 2011, they had already built up the technology required to document it safely.

In the summer of 2011, an irregular wreck anomaly was registered with side scan sonar approximately 12 nautical miles northeast of Öland. In October the same year, the first ROV survey was conducted together with MARIS, the Swedish Defence University, the Maritime Museum and Kalmar County Museum. The identification was confirmed by Erik XIV's coat of arms with the double Vasa-sheaf on one of the scattered cannons, and by linking a unique 20-pound culverin to Mars's roster from May 1564.

The wreck lies at 75 metres depth, with its shallowest point on the port side at 66 m, surrounded by scattered objects and fragments out to about a 100 m radius. About two thirds of the hull is preserved on the bottom thanks to the Baltic Sea's low salinity — including the large sterncastle that shows Swedish great-ship construction from the era of Gustav Vasa and Erik XIV.

Ocean Discovery began testing photogrammetry on smaller objects — cannons, carriages, individual details on the wreck. It worked. The next step was attempting to model the entire wreck. It took several years and required an international team of technical divers. Each dive was limited to 20–30 minutes of bottom time at 70 metres depth in total darkness, with flash light reaching no more than two metres.

Once the method was proven, Ocean Discovery equipped an ROV with the same cameras and methodology divers had used. That opened the door to depths, environments and wrecks divers could never safely reach. The experience from Mars is the basis of Ocean Discovery's work today — from M/S Estonia to HMS Cassandra.

The Mars project is scientifically led by professor Johan Rönnby at MARIS, Södertörn University. Niklas Eriksson has provided the ship-archaeological analysis and Ingvar Sjöblom of the Swedish Defence University has identified the cannons. The Mars wreck was rediscovered in 2011 after two decades of joint searching by Richard Lundgren, Ingemar Lundgren and Fredrik Skogh. Ocean Discovery has since formed the project's operational core: development of photogrammetry at extreme depth as a method, fieldwork and technical diving at 70 metres depth. The international dive team captured 50,000+ photographs; Ingemar Lundgren has carried out all post-production and built the 3D model on which the scientific reconstruction rests. Results have been published in three field reports (2012, 2013, 2015) and in peer-reviewed articles in the International Journal of Nautical Archaeology.

During Phase II in 2012, around 30 people from Sweden, England, the USA, Poland, Norway and Denmark took part, deployed across three vessels. 94 dives were carried out, 47 hours were spent on the wreck and 141 hours in decompression. His Majesty King Carl XVI Gustaf visited the field work on board in 2012, photographed one of the recovered silver coins and met the Mars team. The coins were later analysed by Kenneth Jonsson at Stockholm University.

The project has also been portrayed on film. Deep Sea Productions documented the work in "Mars the Magnificent — Battle of Giants" (also known as "Mars Makalös" in Swedish), 60 minutes, co-produced with SVT, ZDF and ARTE and premiered in 2015. The film follows both the ship-archaeological research and the dive team's work at 75 metres depth.

Ocean Discovery collaborated with Västervik Museum to build the exhibition "Ships of the Vasa Kings — the maritime 16th century" where Mars Makalös is the centrepiece. Visitors today can virtually dive to the wreck with VR goggles — move across the soot-blackened oak timbers at 75 metres depth without leaving the museum.

The photogrammetric models have also been 3D-printed as physical scale models that visitors can touch. The combination of digital and tactile experience turns an inaccessible wreck into something visitors can study in detail and physically handle. The exhibition is a collaboration between Västervik Museum, MARIS, the Swedish Defence University, Stockholm University and Ocean Discovery.