Cancún, Mexico!
You will need to book transportation from the airport to Puerto Juarez. Here are a few companies that offer transfers:
Some hotels offer Door to Door transportation including transfers and ferry. Please check with your hotel if they have this service!
The ferry leaves every 30 minutes from Puerto Juarez and is a 30 minute ride over to Isla.
If you book your transfer with CARM or USA Transfers, they have an option to purchase your ferry ticket through them. Otherwise, you can book directly through Ultramar online or at the ferry dock.