The Powerhouse Stretch
(Thanks to Brookline Rowing for this excellent description).
Some of our races run on the “Powerhouse” stretch of the Charles: A 1000-meter straightaway starting just downstream of the Weeks footbridge and ending just below the Riverside dock and boathouse. There is excellent race viewing, and you can pick your spot to see early, middle, or late stages of the races: along the Cambridge riverbank or from either of the Western Avenue and River Street bridges.
There is no designated parking for the course, and public parking can be scarce.
The map below is specific to the Cromwell Cup, but it’s substantially correct for other events: