FORT LAUDERDALE ­— Atlas Ocean Voyages is coming off its best week-long booking period ever, during which it doubled its occupancy for the upcoming Antarctica season.

The small-ship, yacht-style expedition and cruise line attributes the success to a combination of factors: pent-up demand, the uniqueness of the destination, the value of yacht-style expeditions, and its recent ‘Second Guest Sails Free’ Labor Day offer, which has been extended for another week, through Sept. 13, due to its strong response.