Joel Andrews, 24, of Caldicot, Monmouthshire, was last seen at the Fernworthy Reservoir area near Chagford in the early hours of Sunday.
Specially trained officers from Devon and Cornwall Police’s Tactical Aid Group and Local Policing team are searching the area he disappeared.
Police said his disappearance was described as out of character.
Mr Andrews was wearing a grey Animal hooded top and jeans and a dark green waist-length jacket.
Det Insp Brett Mitchell, who is leading the inquiry, said: “We now know that Joel was last seen at midday on Sunday 22 May and he was still at the site where the rave was held.
“I would urge anyone who attended and may have seen Joel to please contact police as they may have a vital piece of information that will allow us to find him.”
His cousin, Emma Scott, said it was “really nice that people are putting in the effort”.
She said: “Everybody’s pulled together to help us try to find him.
“The more coverage we can get the better, because we just want to get him home now.”
A Facebook page has been created by friends who joined the search for Mr Andrews.
PLEASE GET IN TOUCH WITH THE POLICE IF YOU HAVE ANY INFO, ALSO IF ANYONE HAS ANY PHOTOS FROM THE NIGHT PLEASE PASS THEM ON EITHER TO POLICE OR VIA FACEBOOK GROUP JOEL ANDREWS.
THANKS
