Be prepared for “red light/green light” security procedures prior to boarding the ferry from Cancun to Isla Mujeres.  Starting April 1, 2019, passengers will be subject to a random search of their belongings using the antiquated system once very popular at the Cancun airport–push the button and get a red light, your belongings are searched prior to boarding.  Get a green light you are good to go.  Authorities are contemplating using the same procedure when taking the ferry from Isla Mujeres to Cancun.