Welcome to cruise-chat. Ships that do call on Cancun anchor about a mile off shore and tender in. There are actually 2 locations that are used as tender ports. One of them is located at the 7.5 Km Marker and the other is a bit further north across from Isla Mujeres. I know that the Mariott Casamagna is at the 14.5 km marker. I don't know if there is more than 1 Marriott in Cancun, but hope that info helps.