Abstract: A blast hole liner comprised of a single length of waterproof, flattened, longitudinal tubing having an open upper end and a lower end portion terminating in a bottom edge folded about its midpoint with resulting edge halves joined together to define an upwardly open weight pocket. The liner is provided with a transverse seal above the pocket. The latter seal may be located closely adjacent a horizontal crease in the tubing formed by doubling the same back upon itself. In one embodiment, manufacture of the liner from a length of tubing requires no further cutting or slitting of the tube. In another embodiment, a second length of tubing, substantially congruent with the first-mentioned tubing length, may be provided to improve the strength and waterproof nature of the liner and to protect the innermost length of tubing from becoming torn or punctured.