From Horrocks' Hide at Pennington Flash generally there between 7:30am and 8:30am - there's one there regularly at the moment with good photo opportunities - have a look at my Flickr site for what you can get. They also appear regularly at all the other hides although they are generally much further away.
Grove Road in heyrod has a small path leading along the river side in the direction of Stalybridge. It's only about 100m stretch but had good views in past