The sad discovery was made at the Cassio Wharf marina off Rickmansworth Road in Croxley Green on Monday (4th October).
Police are treating the death as non-suspicious.
Commenting “our thoughts are with John’s family at this difficult time.”
Though the body is yet to be formally identified, Mr Gilboy’s family have been made aware.
Detective Sergeant Tony Quince, from the Three Rivers Local Crime Unit, said: “We are very sad to confirm that a body, believed to be that of John Gilboy, was found in the water on Monday.
“Mr Gilboy was reported missing on Friday 1 October and we had been making enquiries to trace him over the weekend before the sad discovery earlier this week.
“We are treating his death as non-suspicious and are preparing a file for the coroner.
“Our thoughts are very much with John’s family and friends at this very difficult time.”