White-beaked Dolphin?

Some more pictures of the pair of dolphins seen off Caol Ila (see earlier positing) have emerged (thanks Kate!) and while they still do not provide the definitive answer, they perhaps suggest White-beaked Dolphin (Lagenorhynchus albirostris) - a cold water cetacean that while unusual (to say the least) in the Sound of Islay, is perhaps a little more plausible than Risso's (Grampus griseus) although Risso's remains a possibility.  These new shots are higher resolution than Nick's originals and I think we can now discount Bottle-nosed which is the dolphin most usually found around Islay.

These are shots of White-beaked strandings.

Common Dolphin (Delphinus delphis), which is of course not even slightly common off Islay, is another possibility, but the initial photo from Nick seems to show an animal without a beak, or at least with only a very short beak....

Risso's Dolphin?

We are grateful to Nick Morgan for these camera-phone photos (which I have cropped) of a pair of dolphins heading up the Sound of Islay.  Shots were traken from Caol Ila. 

This was the first shot I received....  On the basis of this shot, I was (unsurprisingly) unconvinced that this is a Bottle-nosed dolphin - the body shape is not quite right, there is no sign of a beak and the flanks are marked.

I therefore asked Nick if he had any more shots, and he sent these two...

While these reinforce the impression (to my mind) that these are not Bottle-nosed, they do not perhaps give many more clues than the first as to their actual adentity....

Does anyone have any ideas?

Nick has a very experienced yachtsman friend who reckons they are Risso's.  I have never seen Risso's apart from pictures.  Any comments anyone?

Cheers
Carl