A charity-funded Christmas tree, placed outside the Chichester Canal Trust centre, was stolen on Sunday night (December 2).
It was one of two matching trees brought in for customers to enjoy this year, and Sarah Berryman, canal centre manager, said the theft greatly angered her.
She added: "You have to be pretty low to steal a Christmas tree, particularly when it's for charity. That's what made me really angry.
"We always try to do something different each year. We did want to put an arch over the top of the centre, but the volunteer who planned to do it needed to go for an operation. We decided to put these trees up instead."
In a tweet after discovering the theft on Monday morning, the trust wrote: "Bah humbug to the person(s) responsible."
The tree has now been replaced thanks to £45 worth of donations from volunteers and customers.
Sarah added: "Luckily we had the help of generous volunteers and customers but we did have to sacrifice some of the lights on the other tree so that it matches. We have now chained both trees down to the ground."
As a message aimed at the thieves, the centre has left a note on a green cone outside its café.
The note reads: "You have stolen our Christmas tree that was displayed outside our café for our customers and all the children that attend our Christmas trips, including the disabled and adults and children with special needs.
"You know how to ruin their Christmas experience at Chichester Canal. We are a charity with volunteers who give up their time at Christmas, making children and families happy."