Fly into Cozumel or into Cancun and take a ferry from the Riviera Maya to Cozumel.
Year-round sunshine lends itself to temperatures that range from 68 to 86 F October through March and 75 to 91F April to September.
To be married in Cozumel, you must stay a minimum of 72 hours. A valid passport and an original copy of your birth certificate must be provided. Death and divorce decrees are required if applicable. Ask your romance expert for full details or you can view requirements at: http://www.visitmexico.com/en/weddings/legal-requirements-to-get-married-in-mexico