I followed the advice from this site, and went snorkeling from the shore out towards the wrecks in the buoyed off area. They are quite easy to spot as this is where all the tour boats stopped. I'm not a particularly experience snorkeler - its about the 7th time I've done it. I did find it quite fun swimming out over the shipwrecks, although on the way back it was quite difficult getting through the surf when you're a bit tired. The visibility wasn't great from the surface, you could see all the way to the bottom but it was a little hazy. I did dive down a couple of times and the photos I took then were much better. There were a lot of different types of fish.