Cozumel is far better than Hawaii, for SCUBA diving

The visibility of Cozumel can be 100ft or more and such days are common in Cozumel.

Hawaii, if you are lucky, you get visibility of about 60ft.

Anyone who is a certified SCUBA diver would rate Cozumel far above Hawaii.

On top of that, Hawaii does not really have coral - the water around it is too deep for coral to grow.

Another thing about Cozumel is, it is drift diving - the sea current carries you and you "drift" - you start at point A, and the boat will pick you up at point B - diving boats at Cozumel do not anchor - for 2 reasons - the drift, and also not to damage the underwater environment.