COZUMEL

You can check most of dive  centers online or when you get there.
You can pay with CC, US and there are plenty of ATM to withdraw in Pesos or US$. Beware to only use ATM inside banks or supermarkets.

Heya Mick,

My husband and I have been loitering on Cozumel for almost two months now and he's just finished his Dive Master course through PADI with Cozumel Dive School [CDS] so my answers below are based on our experience here to date:

1/ What are prices for the open water PADI 2 day course? - USD$349 through CDS but it looks like it could be up to 4 days - check out the link here http://www.cozumeldiveschool.com/courses.html

2/Does everyone accept US dollars?  Pretty much - but you'll get ripped off of the exchange rate most of the time so we recommend converting to Pesos - the ATM machines will actually dispense in Pesos so that's nice and easy.

3/Are there ATM machines?  Yep.

4/ls it OK/accepted to pay with a Visa debit or credit card? Yes - at supermarkets and the swankier restaurants and establishments, not at the wee local little eateries and cantinas.

5/Other than diving & bars, what else is there to do in/at/on Cozumel?  Snorkelling of course - rent a car and head out around the island - there are a few national parks - Chankanaab, Punta Sur that are well worth exploring, there are Mayan ruins at San Gervasio, there is a Tequila tour and chocolate factory tour, you can even go for a rise in a  tourist 'submarine' (no kidding) if you have people in your group that aren't divers. There is a traditional mayan sweat lodge as well if you want to try a Temazcal ceremony.. quite a bit to do really! 

Look up Cozumel4You on Facebook and join the group - it's a great place for you to ask questions / find out what's happening on the island.

Cheers,
Ambili