Then you will be less impressed with the beach in NV as it is also nothing like PDC, Caribbean or Maui. PV is a wonderful place to visit and we love it but if the beaches are the most important thing to you I'm afraid you will disappointed.
Actually, the water in Cozumel is normally even clearer than either of the locations you mentioned. However, on the island itself, the beaches aren't as good as those locations, and the water drops off a lot faster, so the color from the shore doesn't look as pretty. It takes shallow, white-sand-bottomed, beaches to make the color you're referring to - not just clear water...
I'm a scuba diver, and I've never seen water as clear and beautiful as the water in Cozumel - blew the mainland away.
In PV, the water is not Caribbean clear. It's greenish underwater, but looks very blue on a sunny day from a boat - just a deep blue, not the aquamarine color of the Caribbean. From the shore it looks more greyish-blue due to the color of the sand.
The water is also cooler than those places you mentioned.