Lake Gaston is 34 miles long and only about a mile across. It straddles the Virginia/North Carolina state line with the Eaton Ferry Bridge about midway. It is easiest to map showing an Eastern half and a Western half. Like all Google maps, this one can be zoomed-in to show more details. To show marinas and boat ramps, click here. Or campgrounds, here. Or golf courses, here.
For on the water mapping, we suggest this map from Navonics.