I am not a diver. I did snorkelling only. But L.E.I. is the only spot on the Great Barrier Reef that runs three scuba boats each day. (I was told by the divers whom I met.)
The snorkelling was beautiful. Sea turtles, manta rays, all different kinds of coral and fish. I brought my own, but I believe they said they have prescription goggles available. Oh, the snorkelling equipment rental is also included in your room fee. You do have to pay extra for the boat ride out to the reef though. (I think it was about $7 US for the ride.) If you have never snorkelled before, they do have a mini lesson in the pool on the island before you set out. I saw several people who had never snorkelled before. The guides on the boat went into the water with them and led them around by a life saver ring. I don't know if that's common on reef resorts, but I thought it was awfully nice.
The island does have scuba lessons. I think there were beginner lessons and also lessons for certified divers who wanted to advance to the next level.