A central venous catheter kit enables health care workers quickly and controllably gain ultrasound supported access to vascular tissue for catheterization. Ultrasound support requires gel for reducing acoustic impedance and reflectance loss, which gel is included in the kit, as well as at least two newly conceived devices, the first for gripping the guide wire in an otherwise gelled environment, and the second for marking the skin for proper needle localization. State of the art kit components are thus included in the kit, in addition to the scanning gel and the noted device(s). The devices each comprise certain finger- or digit-grippable structure, and textured surfacing for enhancing the frictional contact between the user's digits and the devices.