According to the Virginia Department of Wildlife Resources, the Dudley Amos Road boat ramp in Franklin County is a concrete boat ramp that provides access to Smith Mountain Lake. It is located at latitude 37.05137253 and longitude -79.66314697.

The boat ramp is reportedly 16 feet wide, which should provide ample space for most watercraft. However, it's always a good idea to check with local authorities and observe posted signs to confirm any size restrictions or other regulations that may apply.

As for the types of watercraft permitted on Smith Mountain Lake, the Virginia Department of Wildlife Resources notes that motorized boats, canoes, kayaks, and other non-motorized vessels are all allowed on the lake. However, certain areas may have specific rules or restrictions, so it's important to check local regulations before launching your boat.