text: although sound travels faster in water than in air, why don't they easily penetrate through water? can ultra/infra sound waves penetrate easier? sound actually passes through water pretty well--that's why navies use sound to find submarines.  in general, lower frequency sounds travel further. i seem to remember reading once that humpback whale songs, which are at very low frequencies, can be heard across entire oceans, but i'm not sure that's true.  you might think sound doesn't penetrate through water well because sound does not move well from air to water (or vice versa). sound tends to bounce off surfaces where materials of different densities meet. so, if you're underwater, it's very hard to hear things above water.