At launch stations, the six pods slide underneath Thunderbird 2 until Pod 4 is in position. Thunderbird 2 settles down on the Pod and clamps tight ready for launch. On arriving at the danger zone, Thunderbird 2 drops the Pod onto the water. During the flight from Tracy Island aquanaut Gordon Tracy has transferred to Thunderbird 4, and operates the Pod door. Thunderbird 4 is launched down the extended slipway.