Holt's shoulder injury
The day before his disappearance Holt was playing tennis with friends in Portsea and a number of them later told police that he seemed to be in pain. Holt's personal physician had examined him only days before his disappearance stating that he was in good health.
One of Holt's friends at Portsea was John Cloke, a leading orthopaedic surgeon from Melbourne. While police never interviewed Cloke, he kept evidence that Holt was suffering from pain, numbness and weakness in his right shoulder and arm from a disc problem in his neck, pressing on a nerve. Holt dulled the pain by taking a morphine and aspirin mixture. Cloke believed this shoulder injury could well have impaired Holt's ability to swim strongly in rough seas.
This clip is from the documentary The Harold Holt Mystery (Ten Network, 1985).