This is also a source for grazing goodies while we travel. Remember that most items will be transported in waterproof bags on the roof of the van. Not a good place for chocolate. When in Alaska all food containers must seal to keep the smell from the bears. Each individual will pay for personal passenger fees and food on the ferry.
Hot water is always available in the snack bar.
A Thermos with instant cereal or pasta is workable. We found that the meals are acceptable and not terribly expensive. Cliff has found it easiest to eat at the restaurant or snack bar while on the ferry. Twice a day you are usually allowed access to the deck. You cannot count on that so essentials need to be with you.