A pneumatic sonobuoy launcher adapted for simultaneously storing, and sequentially and independently launching, at least two sonobuoys includes a barrel with a closed back end, an expulsion end opposite the back end and an interior sonobuoy-guiding channel extending between the opposed ends. The channel is adapted for storing a series of sonobuoys including rearwardmost and forwardmost sonobuoys stored, respectively, closest to the back end of the barrel and closest to the expulsion end of the barrel. Each stored sonobuoy occupies a distinct region of the channel separated by an interval from at least one other region. An expulsion-gas delivery system includes at least one valve that is selectively connectable into fluid communication with an expulsion-gas supply and is pneumatically switchable from at least (i) a first gas-channeling state in which expulsion gas introduced through the valve is directed to a first interval between sonobuoys to (ii) a second gas-channeling state in which expulsion gas introduced into the valve is directed to at least one of (a) a second interval located to the rear of the first interval and (b) a location within the channel behind the rearwardmost sonobuoy. A feedback conduit communicates pneumatic back pressure created upon the expulsion of a sonobuoy to the switchable valve in order to switch the valve from the first gas-channeling state to the second gas-channeling state for the launch of a subsequent sonobuoy.