A "classic" in the saltwater plug offerings.
This plug is more effective when cast in heavy current and immediately jump started by a moderate jerk of the rod tip to get the plug to "bite" and start its descent. Use a slow and steady retrieve as the plug works from side to side for about ten to fifteen feet; then return your rod to a forward position pointed at the plug and allow the Darter to float back to the surface. Your line will need to be slacked to allow this but be ready as strikes often occur with an erratic left-to-right motion as it is retrieved. This is Stan Gibbs' most effective retrieve but you can experiment with different tempos and rod motions to find one better suited for the circumstances.