Re: free boat ramps lake champlain
Try this one out: Malletts Bay Public Boat Ramp, 980 West Lakeshore Drive, Colchester, VT 05446.
There is also a ramp at the intersection of the south end of Shelburn Bay and Bay road (just south of Burlington.
The only difficulty is if you need to leave a truck and trailer. Some places allow long term parking other may frown on it. I'm not sure about this one.