There are a few snorkeling spots in Teluk Pauh, accessible from either Perhentian Island Resort or Coral View Island Resort. Just pick one spot and snorkel for a few minutes. If you are not happy, just look out for another.
From my various snorkeling trips, I think by far, Teluk Pauh offers the best marine life variety and excellent visibility. The types of hard corals that I saw were various species of Acropora sp., table corals (Acropora hyacinthus), green and brown staghorn corals, two or three varieties of sea anemone, cabbage coral of Montipora florida, large clams, etc.
The fish variety was also astounding. I spotted common tropical damselfish, a group of gold-saddle rabbitfish (Siganus guttatus), thousands of fry fish or anchovies, virgate rabbitfish (Siganus virgatus), spinecheek goby (Oplopomus oplopomus), slingjaw wrasse (Epibulus insidiator), eight-banded butterflyfish (Chaetodon octofasciatus), slender needlefish (Platybelone argalus, often mistaken with either swordfish or barracuda), blue-lined damselfish (Pomacentrus sp.), yellow-lined damselfish (Neoglyphidodon sp.), etc.
Teluk Pauh is also famous for spotting turtles. I managed to see 4-5 of them grazing at the sea floor and one huge green turtle (Chelonia mydas) swam past me, escorted by a school of juvenile golden trevally (Gnathanodon speciosus) providing a glorious photo opportunity!
Also at the shallow beach fronting Perhentian Island Resort, there are a few sea anemones and clown anemonefish (Amphiprion percula) very close to the water surface, also another excellent photo moment!