Cruising with 9 month old

We have a Caribbean Cruise booked and our daughter will be just under 9 months old when we go. Anybody cruised with a baby before? We travel a ton for my husbands job but have only been around our state (WI) and MN. We will be driving to New Orleans which is a 16 hour drive and planning to do most of it overnight while she is sleeping. Just looking for tips on making the long car ride better or what we should pack! I think I will get a backpack diaper bag instead of my regular one but that's the only thing I've thought of so far. Also, what are your 9 month olds doing as far as food? We are EBF and haven't started solids just yet (she's current 4.5 months). Would she still be on purées at that point or eating table food? FTM, not sure what will be happening at 9 months! Cruising with Carnival, if it makes any difference. Thanks!