The Answer..No. They used references from a rare 12th century manuscript, the Libellus Plumbeus which clearly shows a floating "island" and gives a full and indepth description of thier uses and users.
I have been given access to this document and have been able to recreate one of the scenes shown as shown below.
|Here we see a farmer, who after helping to secure the anchor rope is asking wether his ploughing is straight. Life was much more simple back then eh??|
|All the buildings of the islands were built of Welsh blue stone, which is thought to contain magical powers. The tower holds the winding gear for the anchor rope and is a common feature of the islands.|