Passengers used a torch to scan the water and soon found Mr Jackson but, while a tender was put in the water to retrieve him, he disappeared.
Central Queensland Rescue and local police co-ordinated a search using boats and a helicopter.
Mr Jackson snr said their son, who grew up in Katikati and attended Katikati College, was the baby of the family of seven children.
Their daughter in Katikati broke the news to them after Australian police were unable to contact them.
The Jackson family home is in Katikati but they have been working at a new gas plant on Barrow Island, about 50km off the coast of Western Australia.
They have flown to Queensland.
"It was such a shock. We still can't believe it.
"We still don't know what really happened to Jonathan other than what police have told us, that he fell overboard," said Mr Jackson.
Mr Jackson said Jonathan had worked on two other ships in the Whitsunday Coral Cruises fleet before becoming a trainee chef on Pacific Sunrise - a job he was relishing, his father said. He and his wife have found some consolation in knowing Jonathan was pursuing his passion.
Mr Jackson says once his son's body is released he and his wife will take him back to Tauranga and begin to make arrangements for his funeral in Katikati.
- APN
