I am heading out on a cruise ship. I will have my personal Iphone 4 with me. What settings need to be changed that will allow the phone to accept calls and/or text messages but not have any data (app notifications, etc.) come through? My goal is to be able to have home reach me or me reach home but that's it. Hope this question makes sense. I do understand that there is text message charge or air time for a phone call if indeed used.