Here's a couple of them that Bill Aspin did manage to nail with the camera
This bird stood out at about 700 metres with bins the bill was so obviously long and pale
Even though it was close (about 250 metres) this one wasn't easy due to the light conditions. We had 3 other birds like this including 2 together but Bill couldn't get anything with the camera to make them worth claiming.
Ken Shaw and Andy Carroll who have pretty much been instrumental in re-writing the status of White billed Diver have told me in the past that they like deeper water than Great Northern, based on birds they have found in spring from land on the west coast of Scotland. BWP states that the usual depth for Great Northern is probably around 4-10 metres but that birds have been caught in nets up to 70 metres down. Being on a boat with all sorts of electronic gauges we've checked the depth for Great Northerns and although it's only a small sample size they seem to be in water up to 25 metres deep. The White bills however, including all the probables have been in water between 36.7 and 46 meters depth. If the probables were all White bills that's a sample of 10 birds this year in water with shallower areas nearby that they appear to shun, we've also never seen one with a Great Northern, they do seem to keep apart from one another. OK so it's not Martin Garner's Birding Frontiers blog but it's all interesting stuff.