thanks guys.
That was about 4 meters away.
I heard them whistling and crawled up to the very small banks above them. The wind was strong from their direction so they couldn't smell me or see me.
Their eyesight isn't the best, so they usually smell or hear you first, unless they see you against the skyline.
I crawled back, after a quick couple of photos and they were none the wiser.
Have any of you been watching "Storm Born" on BBC 1, It includes a lot of footage from Shetland including Otters and Orcas, well worth a look.