Tim writes: this is a Grey-headed Albatross photographed at Shag Rocks, which is 150 miles west of South Georgia, where it breeds.
It is a rare albatross whose world population was estimated at 250,000 individuals back in 2004, but the population is on a downward trajectory so it is likely to be much rarer than that now, largely due to fisheries by-catch. It has been classified as endangered by IUCN. It is the same size and general appearance of Black-browed Albatross, except that it has an all-grey head and a yellow-edged dark bill.
Its scientific name chrysostoma translates as gold mouth, and the generic name Thalassarche means commander of the sea.