Flying Auckland to Brisbane about two thirds across I have seen this reef several times this time I had my phone and got a quick shot. It turns out this is the southern most coral reef on the planet and extremely remote. Known for wrecks and sharks. There is a 400m long area that sits one meter above water. You can visit these reefs and Lord Howe Island on a 7 day salients out of Southport for around A$3k. See the link. Elizabeth Reef Info
In the top picture you can just see another reef called Middleton.