Up to 30 detectives and officers have been involved in the search for a woman who has been missing since Wednesday.
Yvonne Turner, 59, left her home on the Walshes Farm Caravan Park, off Dunley Road, Stourport, Worcestershire, at about 0945 GMT.
Severn Area Rescue Association was brought in to help scour the river basin area and river banks.
Mrs Turner is 5ft 5ins tall and of large build with shoulder-length, dark, greying hair with a fringe.
She was wearing a red, waist-length jumper under a red three-quarter length, zip-up anorak with pockets at the front, brown trousers with a grey, square pattern on them, and black, calf-length suede boots.
Police have been focusing on the area around the caravan park as she was on foot and had no money with her or means of transport.
Specialist dog handlers have been involved in the search, as has the force helicopter, West Mercia Police said.
On Thursday Mrs Turner's husband, Brian, said she had gone off before for a few hours, but had never been missing for this long.
Mr Turner added the couple, who have been married for 31 years, had decorated their home for the festivities, bought each other gifts and made plans to have Christmas dinner at a pub.