He spent two years searching the seabed with dredges and plummets. Without any results. But he got lucky that day. A piece of black wood surfaced with the plummet.
On 4 September the Navy, led by Per Edvin Fälting started diving in the area. He discovered a large wreck during the first diving session. The wreckage of Vasa.
During the following years parts of the wreckage were brought to the surface, including a figurehead, a gun and sculptures.
At the same time preparations to salvage the ship were under way. The divers flushed six tunnels through the mud under the wreckage – and during the salvaging steel cables were drawn through the tunnels. The steel cables were attached to lifting pontoons on the surface, which would lift Vasa from the seabed.
Vasa was lifted from the seabed at the end of the summer of 1959. She was lifted to shallower water in 18 stages. From a depth of 32 metres to 17 metres.
However, it would take roughly a year and a half for the ship to return to the surface.
24 April 1961 was the long-awaited day. Swedish and foreign press was prepared, along with radio and TV crews, and thousands of spectators. The Swedish public service television company SVT sent its first live broadcast and at 09:03 all of Sweden could see images of the first parts of Vasa appearing above the surface of the water.
Anders Franzén and Per Edvin Fälting were the first to step on board, 333 years after Vasa sank.
She floated on her keel on 4 May, after being sealed and emptied with powerful bilge pumps. She was piloted towards a dry dock, where she was placed on a floating pontoon. The same pontoon she still rests on.
Anders Franzen investigated several other wrecks than just Vasa. He has found several.
• The warship Kronan
• The warship Riksäpplet
• The warship Resande Man
• Lybska Svan.
Franzén had strained relations to the Maritime Museum, which for a long time seemed to regard Franzén as an unwelcome competitor, while the Swedish navy and the city of Stockholm were a lot more interested. Therefore, Franzén never worked for the Maritime Museum, but was given a position at his alma mater KTH, which also recognised him with an honorary doctorate in 1983, KTH's Great Prize in 1988, and a personal title as professor (approved by the Swedish government) in 1992.
He was a founding member of the Sea Research Society and served on its Board of Advisors. In 1972 Franzén was awarded the Society's research/professional degree of Doctor of Marine Histories (MHD) from the College of Marine Arts.
He is buried in Galärvarvskyrkogården in Stockholm.