Police say they “have growing concerns” for a 33-year-old who has been missing from the Bangor area since Sunday, 1 December.
Multi-agency searches were launched on Monday, 2 December, to find missing Rowan, which subsequently led to his car being found near to South Stack lighthouse.
Searches by the coastguard and police to locate him are continuing.
Sergeant Maggie Marshall said: “I am appealing to anyone who was in the South Stack area on Sunday evening or on Monday, and may have seen Rowan or a turquoise Vauxhaull Astra, to contact us.
“Searches to locate him are ongoing, and officers are keeping in touch with his family.
“Anyone with information is asked to contact us by calling 101, or via our website, quoting reference 48441.”