Among the experiments was use of "Aquamarine" and for shallow water sound propagation research in the Potomac using frequencies of 70—400 Hz and sampling bottom sediment characteristics. NRL's Sound Division developed a ship quieting technique using bubbles produced at the bow using the yacht for experiments. The experiment used a pipe and fire hose with holes to produce the bubble cloud. The technique was found to reduce sound in the 20—30 kHz range by 20 db and was implemented on operational ships.