Your nephew will have a great time and will return home safe and well by observing a few simple rules.. Here are 2.

1. Don't swim outside the flags when visiting the beach. Many tourists meet their end this way. If no one else swimming there do go in the water, especially in the top end.

2. If visiting the outback, at this time of year, water water water.. lots of water. If the vehicle breaks down, don't leave and go searching for help as help could be a few hundred miles away. Add to this, if venturing off the beaten path let someone know of your time of departure and ETA & destination. Maybe a CB radio too.

...other Aussies may add more.