A system for sealing a percutaneous puncture in a blood vessel in a living being and a method of sealing the puncture. The system includes a hemostatic closure, a blood vessel locator device for determining the position of the blood vessel via the percutaneous puncture, and a deployment instrument for deploying the closure within the puncture to seal the puncture. The vessel locator includes means for enabling blood from the vessel to flow therethrough so that the position of the vessel can be rapidly determined. Once the vessel has been located the deployment instrument, which includes a tubular carrier storing the closure, is extended into the puncture to deploy the closure. The closure basically comprises a radiopaque rigid anchor for location within the blood vessel, a compressed collagen plug for location within the puncture tract leading to the vessel, and a thin filament connecting the two in a pulley-like arrangement. The deployment instrument also includes a tamper which is used to mechanically deform the plug within the tract. Once the closure is positioned hemostasis occurs rapidly, thereby locking the closure in place.