HARBOUR SEAL If you spot a seal on a sand flat or tidal estuary, chances are that it will be a Harbour Seal rather than the alternative, Grey Seal. To confirm, take a close look through optics. Harbour Seal has a ‘friendlier’ face, with a concave muzzle. Its eyes are set one-third of the way back from the muzzle, whereas those of a Grey Seal lie at the mid-point. The clincher, believe it or not, is nostril shape: diagonal in Harbour and vertical in Grey.