The bi-plane with a wing walker on top had suspected engine failure during the Bournemouth Air Festival but the pilot put it down in Poole Harbour where 100 boats were moored near Sandbanks ferry.

       The plane sank within a minute but the fliers, from AeroSuperBatics, escaped with minor injuries.

       Libby Chambers was just 20ft from where the Tiger Moth crashed and she helped pull the pilot and his wing walker into her dinghy.

       The pilot, in his 50s, freed himself from the cockpit then helped his colleague, in her 20s. Libby, 43, of Wareham, and partner Alan transferred the pair to a larger boat which took them ashore.

       She said the flier kept shaking his head, saying: "I can't believe what has happened."

       Libby added: "He deserves a medal. I'm not sure how he managed to avoid the rocks and other boats. It would have been horrific."

       Jason Hall, 40, a builder from Hamworthy, was nearby. He said: "The pilot is a hero. There must have been 100 boats tightly packed together and he dropped it into a space the size of a tennis court. The wing lady was already in the plane when they entered the water."

       Flying resumed yesterday on the fourth and final day of the annual show which is watched by hundreds of thousands of people.