It is a small sized container but it is big enough for swaps and is attached to the tree with fishing line as there is no chance of getting the cache back if you drop it!
This cache is easiest to get to from Blundells Road / Gornhay Orchard. There is a quicker route with better parking on the Industrial Estate however, at various times throughout the year (including the time of publishing) there is an electric fence around the perimeter of the nearby access field - it is still achievable but beware with children and dogs if you decide to access the cache from this route.
The cache is located (if you hadn't already guessed!) in the middle of the river. It is not a very big river but please assess the risks and know your own limits before attempting this cache. This area can become flooded following heavy rain, do not try to get this cache if the river has burst its bank or the water is flowing too fast.
The gps under the tree cover is not fantastic but once you are in the right area there is only one island that fits the hint.