Bike Riding If dad is more of an outdoorsman, this might be the one. Provided everyone in the family has a bike of course. There are plenty of parks with bike trails around Sydney, choose your favourite.
Go Fishing Another outdoors activity that dad usually loves, although the peace a quiet part might be missing when the whole family tag along for Father's Day.
If you have enough time, you could even do more than one activity. Remember to stop and get dad a beer on the way home though!
I hope this list of ideas makes this Father's Day one for dad to remember.