Ian, also refrerred to as the young chieftain and the young McGinty, is the son of The McGinty, the landholder who owned the glen in which the Great Northern Divers were nesting in Great Northern?. Ian is initially hostile to the crew of the Sea Bear, but when the destructive intentions of Mr Jemmerling become known, Ian helps to protect the divers.

“Ian’s private hiding-place and look-out ever since he had been a very small boy" is the Pict House above the cove (GN16). They find a box with his diary inside, and Titty works out that it is in Gaelic (GN4). Later when Roger uses the Pict House as a look-out, Ian finds him asleep there and plays a trick on him (GN16).