Cancun actually Isla Mujeres
There is a wide range of rates. At Marina del Sol and Varedero deo Oscar it it is about $350
a month for
water, electricty, cable, and high speed
internet. It is in the
hurricane hole known as Laguna Macax just south of town. All the boats in here survived with minimal damage during that Cat 5 a few years ago.
Puerto Isla Mujeres is a super delux marina just inside the Puerto Abrigo
There are a bunch of
marinas near town but they are all exposed to the wakes of the ferries,etc. and they charge a lot Paraiso,El Milagro,...as much as $1000/month!