Divers mostly find garbage – but literally there have been "golden" times.

Marie Jonsson has been part of the Heritage Underwater Maritime Archeology project, or HUMA, since its start in 2007. It has given her a once-in-a lifetime chance to explore and recover priceless secrets from the deep.

“You sort of recognize the color of gold. But at the same time I didn't dare to think that ‘Wow! we found a golden spoon!’ I started shaking and couldn't use the metal detector any more,” maritime archeologist Marie Jonsson told RT.

A metal detector was hardly needed for another, rather larger find – a 5-meter long cannon – one of the biggest medieval cannons ever found.

As would be expected, recovering pieces of history both big and small from the seabed needs serious funding.

The Danish fleet, whose remains the HUMA divers are examining, went down five centuries ago. It was a time of a big war between Denmark and Sweden for a vital trade route linking Russia and Europe. Ironically, the HUMA project on Gotland Island is being partially fueled by Russian money.

The money comes from another big Baltic project – the Nord Stream gas pipeline. The pipeline is to deliver Russian fuel to Germany – just as merchants once brought riches to Europe from the east in the Middle Ages.

“It's quite expensive to do this research, but the most expensive is to do the conservation of the findings because they have been soaked with salty water. The project budget is about a few hundred thousands euro,” Goran Ankarlilja said.

The team says their work will help uncover a maritime historical legacy which would otherwise have been impossible – with a historic value as priceless as some of the treasures they have already found.