Travelers can double their money with Norwegian Cruise Line's new future cruise certificates, CruiseFirst. This April, guests can
pay $150 for $300 off any six-plus-day cruise that they can book when they're ready. There's a limit of 10 certificates per person. What's more, CruiseFirst certificates are valid for new reservations booked within three years of the original certificate purchase date. The voyage date must also be more than 120 days from the original purchase date.