South of Abingdon, Va is South Holston lake.
Built by the TVA it is a major power generating and recreational facility. The dives are located near a park located just after you pass over the dam. Getting from the parking area to the dive entrance can be a challenge as the path is steep.
Visibility varies but is usually good below a scum layer. About 15 feet down you pass through layer of 3~5 foot visibility coming out at about 25 feet deep. The visibility improves to around 30~40 feet, though dark. A light is helpful.
You can follow a ramp to the base of the dam at about 125 feet. There are some sunken boats along the shore within a short swim if you head away form the dam.