Benjamin Barrett lives aboard the vessel Reremoana and was last seen leaving in his dinghy at around 11.30pm on 26 May. Police and his family have had no contact with him since.
The dinghy is approximately 9ft long, white, with a rounded fibreglass bow, wooden frame, and timber seats.
Anyone who has seen Benjamin or the dinghy is asked to call the police on 105, quoting reference 260527/4669.
Anonymous tip-offs can be made through Crimestoppers on 0800 555 111.
