It's best to wear a wetsuit for warmth, protection and buoyancy and you should snorkel with someone experienced or join a guided snorkel course. Also check sea and weather conditions are suitable.
Once you are in the water it won't take long to be surrounded by fish. Parore and spotties are some of the first seen and as you move further from the beach snapper – very large ones as well as small ones – will soon come around you. Their spots glow bright blue when the sun shines on them.
There is a mix of sandy patches and rocks covered with seaweed. Amongst the seaweed you will see some fish that match the weed quite well like kelpfish, marblefish and butterfish.
Shag Rock around 150m directly off the beach, is a good place to see heaps of fishes especially during high tide. Alphabet Bay on the north-west side of the island also has good kelp forest and fish life. During summer kingfish move through the reserve and hunt on smaller fish.
Dolphins and orca are also frequent visitors and are awesome mammals to snorkel with. You can never tell when they are going to appear.
There is good information supplied by the Department of Conservation at the reserve which will help you identify the fishes you've seen. Marine invertebrates include anemones, sponges, seashells, nudibranch (sea slugs) octopus and much much more.