The Charles River is ready for the rowers.

Starting today, more than 12,000 athletes and tens of thousands of fans will head to Greater Boston’s iconic river for the three-day Head of the Charles Regatta.

Started in 1965, the Regatta plans year round for the annual event from its headquarters in the Cambridge Boat Club. The six-person staff is assisted by some 2,400 volunteers, according to the organization.

Rowers practice for their incoming Head of the Charles Regatta races. (Libby O’Neill/Boston Herald)

Rowers practice for their incoming Head of the Charles Regatta races. (Libby O’Neill/Boston Herald)
Rowers practice for their incoming Head of the Charles Regatta races. (Libby O’Neill/Boston Herald)
Rowers practice for their incoming Head of the Charles Regatta races. (Libby O’Neill/Boston Herald)
Rowers practice for their incoming Head of the Charles Regatta races. (Libby O’Neill/Boston Herald)
Rowers practice for their incoming Head of the Charles Regatta races. (Libby O’Neill/Boston Herald)
Rowers practice for their incoming Head of the Charles Regatta races. (Libby O’Neill/Boston Herald)
Rowers practice for their incoming Head of the Charles Regatta races. (Libby O’Neill/Boston Herald)