I think having seen photos, and having discussed it with others who were there, there's now a feeling that this was a Streaked Shearwater with an amount of dark amount about the rear crown, nape and shoulders which seems unusual, but plausible - everything else looks right for Streaked.
We didn't get really close to this bird, but the photos were everything - thanks to those who took the photos, and please keep coming along!
We will get more rarities, and get better at seabird id, if we we keep going.!
Mike T.
