The partner of a firefighter who went missing on a work night out says his disappearance is "completely out of character".
Police in Sussex are "increasingly concerned" about Anthony Knott, who has been missing since Friday.
The 33-year-old, from Orpington was last seen at a pub in Lewes with a group of 12 London firefighters.
His partner Lucy Otto said: "The longer it goes on, the more worried we're getting."
Earlier, emergency crews began a search of the nearby River Ouse.
'I feel numb'
Speaking to BBC Radio Sussex, mother-of-four Ms Otto said: "I've been asked questions like 'Was he depressed?', but I can categorically say that he was in a happy mood.
"He loved his job, he loved his family, it was just simply a Christmas night out."
Mr Knott was due home at 02:00 GMT on Saturday and Ms Otto said he was "very adamant" he would be home in time as she had to leave for work at 03:00.
The group were moving between various pubs, but he was last seen at 19:30 in The Lamb on Fisher Street.
Ms Otto said: "I just feel numb... it's very strange. It's the not knowing, it's terrible.
"It's quite a small town, so it's just strange that no-one's seen him."
Mr Knott, who is 5ft 8ins (1.73m) tall, was wearing a black long-sleeve top, dark denim coat, dark denim jeans and black shoes.
He has two tattoos, one featuring a Tottenham Hotspur logo on his arm, and the other a wolf.