I have been there a few times as half my family lives there(i would hate being stuck on a rock) and theres quite a few herps. I hadnt seen any snakes the times i had been before until about the middle of last year when i went. Theres a few pics in my album in the personal galleries..unfortunately my memory card malfunctioned and started deleting pictures randomly off it, so not all pics are there.
I saw a few GTS, BTS, Goulds monitors? or yellow spotted monitors? didnt stop to have a look. Green tree frogs. And if you go to Whitehaven beach you will most likely see a lacey or 2 which will usually come up to. There a bush walk on that takes u to a look out on top of the island that has great views. I was about 9 when i walked up there last and dont really remember it all that well, but you will probably see some reptiles.