To see full size copy of the diagram, please click on the thumbnail image.
To tie the ocean plait, first make a copy of the diagram on plain paper, with a hole at each of the points marked.
Next take 80" of 2mm cord and thread it down through hole #1 to about half way. Continue threading one end up at ~2 - down at #3, etc. - until #36 is reached.
Tear away the paper and lead end 'B' along the same path as 'A' until the cord ends. Then take 'A' back along the path of 'B' until you have trebled the whole plait.
The finishing touch is to carefully work out any slack until the mat lays flat and even and the ends have been trimmed and secured by sewing or heat sealing (with nylon or polypropylene cords) on what will be the back of the mat.