SignificanceMany marine populations grow and spread via larvae that disperse in ocean currents. Larvae can alter their physical transport by swimming vertically or sinking in response to environmental signals. However, it remains unknown whether any signals could enable larvae to navigate over large scales. We studied larval responses to water motions in closely related snails, one from turbulent coastal inlets and one from the wavy continental shelf. These two species reacted similarly to turbulence but differently to waves, causing their transport patterns to diverge in wavy, offshore regions. Contrasting responses to waves could enable these similar species to maintain separate spatial distributions. Wave-induced behaviors provide evidence that larvae may detect waves as both motions and sounds useful in navigation.