On sails and bluestone transport

This is a very interesting article which I came across by chance:

https://www.hakaimagazine.com/features/no-wool-no-vikings/

More than once, on this blog, we have discussed ropes and sails and sailing techniques, since some people think it was just a doddle for our Neolithic ancestors to transport 80 bluestones by sea from Pembrokeshire to the coasts of Somerset or somewhere else in SW England.

The article explains how difficult it was, even in Viking times, to make sail cloth (using wool) which was strong enough, light enough and manageable enough to catch the wind and cope with great stresses in a hostile marine environment.  Early sails -- in the Neolithic and Bronze Age -- are thought to have been made with woven flax.  But the fragments of woven flax that have survived suggest that there was a size limit on what could be woven -- which would have necessitated stitching together lots of small woven items in a sort of patchwork effect.  Animal skins might also have been stitched together,  but they would have been very heavy indeed.

All very instructive.  I'm more than ever convinced that rafts or other vessels with sails could not realistically have been used 5,000 years ago to transport large lumps of bluestone from North Pembs all the way to the Somerset coast.  Neither the development of floating vessels,  ropes or sails had reached a sufficiently technologically advanced stage.