The Siege of Pinchgut

British action thriller set in Sydney, Australia and starring Aldo Ray as Matt Kirk, a wrongly-convicted prisoner who, along with three other inmates, escapes from jail aboard a small boat. When the fugitives run aground on Pinchgut Island, a small military fortress in the middle of Sydney Harbour, a desperate siege begins during which the island caretaker Pat Fulton (Gerry Duggan) and his family are held hostage and a loaded cannon is trained on the city's waterfont.