The Rivers and Tides DVD can be bought in the UK and Europe from:
https://www.curzonartificialeye.com/rivers-and-tides/
and in Germany at http://www.piffl-medien.de/rivers_and_tides/rivers_and_tides.php
in France from http://eurozoomcine.com
The Rivers and Tides DVD can be bought in the US from: