 In early August, "U-5" was sent out from Lissa when the Austro-Hungarian Navy received word from a reconnaissance aircraft that an Italian submarine had been sighted at Pelagosa.On the morning of 5 August, the was on the surface, moored under a cliff in the island's harbor.When "U-5" surfaced just offshore, "Nereide"s commanding officer, "Capitano di Corvetta" Carlo del Greco, cast off the lines and maneuvered to get a shot at von Trapp's boat.