Dive sequence illustrating the differences between dive clusters and aquatic activity sessions (AAS). Dives of mink 187a (female) from 27 January 2006 were assigned to one of three states using a Hidden Markov model algorithm as in : State 1 (white) dives represent a period of continual diving, State 2 (red) dives represent a period of loosely aggregated diving (an AAS), and State 3 (black) dives are terminal dives in a cluster or single dives. Note, however, that an AAS does not necessarily comprise a series of clusters and may simply be a short series of loosely aggregated dives. Hours of darkness are shown by grey shading. This is a modified version of a section of Figure 2 from .