Give Carnival(NYSE: CCL) credit. Despite one of the toughest periods for travel in recent memory, the cruise-line operator is not just treading water, but actually showing slight profit growth.

For the three months ended Aug. 31, the company gained $0.85 a share on revenue of $1.44 billion, beating the consensus estimate of $0.77. In the same period last year Carnival earned $0.84 a share and recorded $1.49 billion in revenue. It's worth noting that the comparison period from last year predated Sept. 11. The closely watched net revenue yield -- which is net revenue per available "berth day" -- fell less than 1%.

Customers are still booking cruises much closer to sailing dates than last year, which makes it tougher to offer a solid assessment of future sales. Nonetheless, CEO Micky Arison is upbeat about the fourth quarter, predicting a 1% to 3% rise in net revenue yield.

Carnival's quarter has to be heartening to others in -- or reliant on -- the travel industry. From hotel chains to online booking companies to restaurants, a huge part of the economy depends on travel and tourism... whether by plane, train, or automobile. Any indication that things are on the rebound is more welcome than a "clean restrooms" sign after a long drive.