poster size tide cart

howdy all, My 12yo boy is really starting to show an interest in the ocean but can't quite get his head around the way the tides work. I've had a go a explaining the everyday port phillip heads tide charts that you can get from surf and fishing shops, but its a of bit info overload for him. Its hard to see the way the moon, sun cause different tidal heights from a bunch of numbers. Was wondering if anyone knows where i can buy, or download and print, a poster size tide chart that shows the rise and fall in table or wave form, with moon phases etc...ideally the sort of poster style thing i can stick on the back of the dunny door for him.(worked a treat for his time tables!)