Castaway (2010)

Shipwrecked on the isolated coastline of Western Australia, Ryan and his friends set out on an intrepid journey full of mystery and discovery to rescue their kidnapped parents. They encounter previous survivors, become caught up in games of cat and mouse and double cross before being lured into Hamilton's old camp now under the control of Hamilton's former protégé Eli Fox. But all is not lost. Ryan discovers that Eli was not the only thing Hamilton left behind. He also left behind a clue... telling them where he was going and where he is keeping their parents!