You should be able to gain access onboard, but if not, each of the ports has internet cafes you can spend time in. They are much cheaper than on ship too. If there is a port you aren't exactly interested in, this might be the perfect opportunity to do the work. Sorry your vacation can't be one of complete ralaxation. I'd hate for you (or anyone) to have to cancel, but I do know the first several sailings of the Grand out of Galveston are sold out so if you do, someone will be happy to take your spot.