I use the Australia / NZ Navionics app on my android phone when I go to new places, good for coastal bays and creeks. Just download the maps for the area before you go. Simple to use and cheap to buy, $14.99 annual fee. I saved a 14 day track through the Kimberley recently and marked all my fishing waypoints along the way. It does drain the phone battery quickly though, so you need to connect to your main car / boat battery or recharge regularly. It can also be synced with other GPS units running Navionics as well.