The 65-year-old Crib Point man last spoke on the phone to a friend on Saturday, 1 July about 4.15pm, but has not been seen or heard from since.
Police hold concerns for his welfare due to the amount of time he has been missing and the inclement weather conditions he may be travelling in.
Gary is described as about 183cm tall and clean-shaven with silver hair, a pale complexion and light brown eyes.
He is known to frequent local beach and bush areas of the Peninsula.
Search and Rescue crews, together with the State Emergency Service, have undertaken searches of the area today.
Police have released an image of Gary in the hope someone may recognise him and be able to provide information on his whereabouts.
Anyone who sights Gary is urged to contact the Hastings Police Station on 5970 7800 or Crime Stoppers on 1800 333 000.
