Aerial view of Weymouth Fore River. Weymouth Fore River (before 1965): Weymouth Fore River stretches for five miles from the mouth of the Monatiquot River in Braintree to Hingham Bay, about nine miles south of Boston. Most of the river's upper end, from Smelt Brook at the Route 53 Bridge to a point about 0.5 mile upstream of the Fore River Bridge (Route 3A), lies along the Braintree-Weymouth line. The middle and outer sections of the inlet lie along the Quincy-Weymouth line, MA.