The Charles River is one of the most interesting and scenic urban rivers in the US. There are four yacht clubs on the Charles River: Charlesgate Yacht Club, Charles River Yacht Club, Newton Yacht Club, and Watertown Yacht Club.
There is a public boat ramp located next to Community Rowing on Nonantum Rd. in Brighton, but the trip from the public powerboat ramp is a one hour journey to the harbor. Powerboaters who desire more rapid access to the harbor are encouraged to use the Little Mystic Access Area, which has direct harbor access. It is located off Terminal St. in Charlestown and also provides ample parking. Additionally, the DCR launch ramps on the Mystic River behind the Schrafft Building in Somerville and another at the Mystic Wellington Yacht Club in Medford offer faster access than the Brighton ramp.
Gas is available at both the Watertown and Newton YC's and pump-out is available at WYC and at the Charles River (near MIT) and Charlesgate (near the Sonesta Hotel) YC's. Charles River YC runs a pump-out boat which will service boats moored in the lower basin when a steward is available.
Powerboaters on the Charles share the river with a multitude of other craft. From just above the railroad bridge through the narrow channel by the Science Museum and into the middle of the Esplanade Basin the Duck Boats run rain or shine. The sailboats from Community Boating and MIT take over the Basin from the Longfellow to the Mass Ave bridges. Also here are scullers from several universities and private clubs, kayakers from the Charles River Canoe and Kayak site at Kendall Square and Dragon Boats. The Charles Riverboat Company tour boats come out of the little canal next to the Cambridgeside Galleria and run up to about Harvard Square.
Further up river there are lots of canoes, kayaks, and stand-up paddleboarders from the Brighton location of Charles River Canoe & Kayak. and scullers from several universities, high school, public and private clubs. It does not take much wake to swamp a scull so the fact that the speed limit is 6 mph does not excuse such an act. Don't be surprised though if the kayakers head directly for your stern wake as that's the only action they get.