The study have gone through the tens of thousands of ships depicted in petroglyphs, noted lenghts based on the number of paddlers indicated in each, noted mast and sail like structures on some of them, estimated lenght to width ratios based on stone ship burial monuments from the time and more.
We already knew that the ships had a peculiar design, various variants of it is depicted in the petroglyphs and a hundred years ago the lone surviving boat from the era (perhaps another one will eventually be found) was excavated in Denmark. The Hjortspring boat.
Here’s a model depicting it:
Here’s some of the numerous petroglyph depictions of ships:
A side note: My take on the latter one is that it commemorates a sea battle in which two smaller ships surrounded and defeated a larger one. Note that the larger vessel in the middle appears to have just a few full sized and some shortened markings for people, not occupying the whole lenght of the ship as in most depictions. Perhaps those indicate how many were captured essentially unharmed respectively in a wounded state, and indirectly how many fell in battle.
Dan Davis History has got a video up on these Nordic bronze age ships, 18 minutes long and a good watch:
https://youtu.be/LzMawxOiGLc
The study itself can be read here:
https://www.tandfonline.com/doi/epdf/10 ... ccess=true
A maritime capability with sailing ships of this size over 3,500 years ago in Scandinavia is quite interesting to imagine.
