An electrochemical corrosion potential (ECP) probe assembly for monitoring ECP in a high velocity reactor line includes an airfoil shaped ECP cover that improves the streamlines over and around an ECP sensor. The airfoil shaped cover includes flow holes drilled normal to the surface of the ECP cover. As such, the direction of flow of reactor water into the ECP probe assembly is altered to reduce the flow rate internal to the ECP cover sufficiently to prevent damage to the ECP probes. To facilitate use as a retrofit component, the ECP cover may have an elliptical section that is contiguous to a circular section that conforms to the geometry of existing probe wells and probe sub-assemblies.