Fig. 2.

Pictures of the V-tag (version 3) directly after being fitted on the right side of the dorsal fin of a harbour porpoise (a) and during release of the animal (b). Note the magnesium nut on the front pin, the black GPS unit in the middle of the tag and the small ARGOS, VHF and dive logger hidden in the yellow float material. The ARGOS tag on the left side of the dorsal fin is visible in (b), which remained on the porpoise after the V-tag released after about 7–12 days