Are you wanting a regular fireworks cruise, or the Magical Fireworks Cruise for Grand Gatherings? If its the latter the only way for a foursome to do it is to find another foursome (plus) and become a Grand Gathering. That means you have to get a grand gathering number and book the fireworks cruise (they fill up fast) then find people who are going about the same time as you, ask them to join your grand gathering so it is valid. I don't this with another DIS family our last trip. It was fun.