This is the Virginia code for dredging
https://vacode.org/28.2-1203/

7. Recreational gold mining, provided that (i) a man-portable suction dredge no larger than four inches in diameter is used, (ii) rights of riparian property owners are not affected, (iii) the activity is conducted without adverse impacts to instream beneficial uses as defined in § 62.1-10, (iv) the activity is conducted without adverse impacts to underwater historic properties and related objects as defined in § 10.1-2214, and (v) the activity is not defined as mining in § 45.1-180.

This doesn't necessarily state recreational gold prospecting but good to have on your person as well.

https://www.mrc.virginia.gov/regulations/subaqueous_guidelines.shtm#Section_II