David, you surrender your luggage to a porter,it will be delivered to your stateroom- later in the day - mostly because your stateroom probably won't be ready when you board and your bags will be in the way of the housekeeping crew. The bags might even have to go through security before they are loaded onto the ship. You can bring your carry-on with you as long as it fits thru the scanners ( just like the ones in the airport)
David, we were just on the Grand in September and asked the same question. We were told by the staff who very patiently explained that US Coast Guard requires ever item going onto a ship to be screened by X-ray. Also she said that the scanners inside the terminal were smaller and took the hand luggage only and we would be far more comfortable checking our bags because the terminal gets congested and the elevator is small in the terminal. I didn't want to give up my bags but reluctantly did and when we went back to our cabin after lunch, all 6 of our bags were there already. Was not a problem
The x-ray equipment for carry on luggage accomodates very large items. I've carried *everything* on for a cruise before, without a problem. The question is probably more one of whether you really want to try to carry all your luggage or not. I don't happen to mind, so sometimes, I just carry it myself. Other times, I turn it over to the porter.