Yes I agree, but the Scandinavian rock pictures date from 2000 BC to 200 BC. Perhaps the ones showing masts are later and of the Iron Age. The Hjortspring boat was excavated on the farm of that name on the Danish island of Als. Dated to 200 BC, it was 43 ft long and 6 ft wide. Round bottomed and made with five overlapping planks stitched together, but no sign of a mast.

Try and get hold of Landstrom's book from Abebooks or a public library. He knows his subject and the coverage is worldwide. His paintings are all based on actual craft or contemporary illustrations and are breath takingly beautiful and technically detailed.

PS Putting pictures on the Portal to illustrate a forum discussion on TMA means co-operation undreamed of a while ago.

A lot more effective than snide jibes!

>I find the leafy branch theory little unsatisfying

Yeah, doesn't quite ring true. Especially not if you're working on the theory of least effort. Hoisting bushes in the air would be quite tiring, especially in a stiff breeze.

What would have been a precursor to sails and masts?

Sails could have come before masts I suppose, especially in vessels with flexible frames rather than wooden keels, but what would they have been attached to? Could you just hold a small sail and get a decent degree of propulsion? Probably not.

Maybe, if you didn't have a good enough supply of textiles lying about to invest in large quantities of sailcloth, you could use kites made of animal skins.

Or maybe two people, each holding aloft a paddle, with a 'sail' of skins attached to the top of each paddle?

Who knows? Not I. And I can't think of any ethnographic comparisons. But it's fun to speculate.