Abstract: A sonobuoy depth selector utilizes the tension in the attaching cable between the suspended sonobuoy and the supporting float to select the length of the attaching cable. Bobbins are attached to the cable at predetermined distances from the float. The bobbins are also mounted on a solenoid actuated pin which is tapered to cause only the bobbin resisting the tension in the cable to slide along the pin to a release position near the end of the pin. Momentary electrical energization of the solenoid causes the pin to release only the bobbin under cable tension thereby allowing the cable to pay out from a cable reel until stopped by the bobbin attached to the next larger predetermined length of cable.