Carl Hodgkinson, 18, who lives in Nottingham, pleaded guilty to nine counts of robbery at knifepoint on the towpath, and at Nottingham Crown Court was sentenced to four and half years in jail.
He also asked for a further 10 offences to be taken into consideration.
The man had mounted a reign of terror on the towpath, with the resulting publicity of the continuing robberies making it virtually a no-go area, until he was eventually caught.
The court was told that Hodgkinson would typically ask his victims for the time, before threatening them with violence or a knife and demanding personal items and cash, and stole items including a laptop computer and mobile phones.
Acting Detective Sergeant James Bond stated:
"Hodgkinson is a prolific robber, who often targeted vulnerable people and used the threat of violence and knives to instil fear into his victims. This kind of offence is completely unacceptable and the police will seek to take positive action against anyone who commits such an offence."