Wildlife Aid manager Simon Cowell with veterinarians Sara Cowen and Patsy Taylor and oars from their missing boat.
A team from Wildlife Aid were called out to the Ifield Mill Pond last week, to help rescue a swan which had been impaled through its beak and jaw by a fishing hook.
The team took along a rowing boat to help with the rescue .
But they were left up the creek without a paddle after the boat was stolen by brainless thieves.
Simon Cowell, head of the Surrey-based charity, said: "Four of us were out on the rescue in Bewbush and we left the boat on the bank.
"Within 10 minutes some persons of unknown mental ability came and took it away.
"I rang the police on the next morning and we reported it but there is no sign of it anywhere and nobody has heard a thing since."
He added: "A rowing boat is absolutely essential for Wildlife Aid as a lot of our rescues are water-based and we often have to get out into the middle of the lakes and rivers or into marshland."
Despite the setback, the team managed to save the swan which was dangerously close to dying because the injury had left it unable to eat.
But the hook was removed and the swan was released back into the pond.
Police are still looking for the boat, which is six feet long and white, following the theft last Tuesday evening (June 23).
Sergeant Darren Taylor said: "It is despicable because these guys give a lot of their time to help out wildlife that has been injured and some callous thief has come along and stolen their boat.
"If they had any morals they would return it but I doubt they will."
According to Mr Cowell, replacing the boat will cost around £600 and the charity is appealing for help to buy the replacement.
If you are able to support the appeal then you can get in touch with Simon on 01372 377332 or email wildlife@pncl.co.uk.