there is presented an underwater vehicle polymer ejection control valve ambly comprising a valve in communication with a polymer reservoir and in communication with ejection ports . the assembly further comprises a valve actuator including structure responsive to the vehicle in an ascending mode reaching a first predetermined depth in a water column to open the valve to place the polymer reservoir in communication with the ejection ports . the aforementioned structure is further responsive to the vehicle reaching a second and lesser predetermined depth to close the valve to interrupt communication between the polymer reservoir and the ejection ports .