I had the privilege of being a member of a successful landing trip from the North Berwick Seabird Centre on Monday June 2nd. Only about 50% of the trips succeed in landing, because there is no harbour, and the boat somply pulls alongside a steep, slippery set of steps! An awesome experience to visit the home of 140,000 Gannets. The sight, sounds, and smells are unforgettable. The rock itself, of course, is a steep volcanic plug rising sheer out of the water for a lot of its circumference, so it is a spectacular location.
The birds are untroubled by the small group of visitors (not more than about 10) and as long as you keep a couple of metres away, they don't show any sign of disturbance. Amazing photo opportunities, obviously, and you really don't need a long zoom. You get 3hr on the rock, weather permitting, which is certainly an amazing opportunity to learn some Gannet behaviour. There were no chicks in the area we observed, though there may well be by now.
If you're interested, grab a look at my Google Plus photoset on