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Information on dive and pause times and the numbers of dives in a sequence were obtained for six guillemots and single razorbill and puffin. There were marked differences in diving performance between the species with the order of ranking, in descending order of dive and pause duration, being guillemot, razorbill and puffin. For guillemots, 80% of dives were of 20–119 sec duration and 80% of pauses were 0–59 sec; the maximum dive lasted 202 sec. Puffin dives and pauses were much shorter, with 81% of dives lasting 0–39 sec and 95% of pauses being less than 20 sec, the longest dive was 115 sec. Comparisons of diving sequences made by the same individual indicated some flexibility in all aspects of the sequence but there were broad interspecific differences in the organization of the sequence. The puffin generally made a large number of relatively short dives separated by very short pauses which resulted in a high diving rate (1–5 dives/min) and the bird spending 78% of its time underwater. In contrast, guillemots had much shorter sequences with a few long dives and pauses and lower rates of diving (0–5-0-6 dives/min) and proportions of time underwater (61–65%). Guillemots and puffins may forage at different depths and have different foraging strategies.