In the beautiful photo, the mother and son duo are all smiles, while several follow-up snaps show the sprightly youngster exploring the underwater attraction.
Enthusiastic fans were quick to comment on the photos, with one person writing: “Such a gorgeous stunning photo of you and your gorgeous son.”
Meanwhile, another person stated: “Looks like an amazing day out. Loving your character Leah on home and away.”
A third person added: “Photos are lovely @adanicodemou Hope you both had fun.”
Ada’s recent underwater adventure comes after the 43-year-old actor shared several sweet snaps from Johnas' eighth birthday celebration in August.
Taking to Instagram at the time, the doting mum shared a beautiful photo of Johnas posing in front of a spectacular cake, which was shaped like a soccer ball.
“Despite not being able to have a big birthday party Johnas had a great day with an even better cake,” Ada captioned.
Many of Ada’s followers commented on the snap, including her Home and Away co-star Lynne McGranger, who wrote: “Looks gorgeous.”
Ada, who is happily in a relationship with millionaire businessman Adam Rigby, shares Johnas with her ex-husband, Chrys Xipolitas. The former couple split in 2015.