Crews from Fareham and Cosham assisted emergency service partners, including the police, following a report of a person in the water near Delme Roundabout in Fareham.
The alert was raised at 2.49pm and firefighters from Fareham’s water rescue unit entered the water to assist with a search.
However, a spokeswoman for Hampshire and Isle of Wight Fire and Rescue Service said: ‘No persons were found and crews began to leave shortly after 4.30pm.’