A scuba-diver-operated sampler allows accurate measurement of bedload discharge. The new device is a portable pit-type sampler, which is pushed into the streambed by a diver. The sampler satisfies the essential requirement of stability in operation, and because it rests below the bed surface, does not interfere with the flow. Sediment particles are deposited in the sampler as they are transported over the leading edge of the wedge-shaped cavity. The sampler opening is adjustable in size so that it will accept a wide range of particle grain sizes. In initial testing, the sampler performed well, compared to the dune-tracking (sonic depth-sounding) method of Richardson and others (1961). Because the art of scuba-diving has evolved to the point where diving is now an accepted method in scientific and technical investigations, and is routine procedure in many fields, use of the sampler is entirely practical.