At 10:10am on 26 January 1966, the Beaumont children caught a bus to go to the beach. The bus stop was on the corner of Diagonal Road and Peterson Street, less than 100 metres from their home. The bus driver, Mr I. D. Monroe, later confirmed carrying the children on his bus. A woman passenger also noticed them, being able to recall later the colours of the clothes the children were wearing and that Jane carried a copy of the book "Little Women." The bus continued north-west along Diagonal Road, then north along Brighton Road before turning left to travel west along Jetty Road. From Jetty Road the bus turned left and halted at a stop in Mosely Street, only a short stroll from the beach. It was at this point that the children left the bus, at 10:15am.
Nothing is known of the movements of the children during the next 45 minutes, though it is presumed that they had a swim. At about 11am, a 74 year old woman (Woman 1) was sitting in front of the Holdfast Sailing Club building on a bench under some trees. Woman 1 saw the three Beaumont children playing under a sprinkler on the lawn of the Colley Reserve. A man wearing blue swimming trunks was lying face down on the grass. He seemed to be watching the children. About 15 minutes later she saw the man frolicking with the children, who were flicking him with their towels.
At around 11:45am the Beaumont children entered a nearby milk bar and purchased some pasties and a pie, using a £1 note. Mrs Beaumont was later adamant that she had given Jane only six shillings (it was 19 days before the introduction of decimal currency). The children were due to catch the noon bus back home in 15 minutes.
At about 12pm, another woman (Woman 2, who had earlier seen Woman 1), was sitting on a nearby bench. The bench was also occupied by an elderly couple (Woman 3 and her husband) and the elderly couple's 10 year old granddaughter. A man and three children approached. The description of the man matched the man seen earlier by Woman 1. Woman 2 was almost certain that two of the children were Jane and Grant. She was positive that the third child was Arnna.
With the children trailing, the man asked the four on the bench if they had seen anyone interfering with his clothes; some money was missing. They told him that they hadn't seen anything and the man returned to the children. Woman 3 watched them and saw the man dressing the children. She thought this odd, especially when the man pulled Jane's shorts up over her swimming costume, as Jane seemed to be easily old enough to do this herself. At a press conference eight days later, Mrs Beaumont expressed surprise at the same thing. She thought it almost impossible that Jane, a shy child, would let someone else dress her. However, according to the elderly couple, the children seemed very friendly with the man.
Having dressed the children, the man then picked up a pair of trousers and a towel. Woman 2 said that he walked away with the children and passed out of sight behind the Glenelg Hotel. Woman 3 said that he went to the Colley Reserve changing rooms. By this time it may have been 12:15pm.
At approximately 1:45 pm, a visiting man from Broken Hill saw a man and the children leaving the beach. The man matched the description of the one seen earlier.
A postman, Mr T. Patterson, was the final person to see the children. He was in Jetty Road and the children were walking east along the footpath. They appeared to be about to cross the road towards Mosely Street. Mr Patterson knew the children and they said "It's the postie!" The children were behaving normally and there was no sign of anybody with them.
This sighting of the Beaumont children occurred either at the beginning or the end of Mr Patterson's round, at 1:45pm or 2:55pm. The sighting by the man visiting from Broken Hill, plus the fact that the children were walking towards the bus stop at the right time to catch the 2pm bus, suggests that it was at 1:45pm that Mr Patterson saw the children. Contrary to this, however, Mr Patterson later said that the encounter was at the end of his round, at 2:55pm. Either way, Mr Patterson suspected nothing amiss and continued on his way. The children were never seen again.