Tangalooma has so many free activities to play with the family. Table tennis is such a great fun one for the family and it's simple enough for kids of all ages.
Definitely don't bother trying if the winds up as you'll just lose a bunch of balls though.
The roof of the flensing deck can offer some respite from a hot tangalooma day and provide a much welcomed offering of shade.
While it's a free activity, there's still a $20 deposit for equipment hire required at the water sports hut but don't worry, they'll give it back to you once you're done.