I think I will have to take a refresher dive to see some of these great dive sites. I haven't been diving in 11 years since I was stationed off of the Azores islands in the Atlantic. I was originally planning on doing a dive tour in Phuket but instead took the tours of Phi Phi island with some stops for snorkelling with my fiancee. That was her first time snorkelling and she loved it--there's some neat tropical fish in the Andaman.
I really would love to check out Roatan or Cozumel. I don't like the cold water around here. (Northern California)
There is a reason for my 19 visits to CCV with 2 more planned to Roatan and only 2 trips to Cozumel over the same period of time. Better diving dollar...Roatan's only drawback...sand fleas whereas Cozumel doesn't have that problem.
For the additional 25-30 minutes in the air...go to Roatan for diving...for beach lounging go to Cozumel.