(Reuters) -Carnival Corp ( CCL ) raised its annual profit forecast after beating second-quarter revenue estimates on Tuesday driven by resilient demand from travelers booking cruises to destinations including the Caribbean and Mediterranean.

Shares of the company, whose portfolio of cruises includes Holland America and Princess, rose 6.5% in premarket trading.

Cruise operators including Carnival Corp ( CCL ) and rival Royal Caribbean Group have been expanding their portfolio of carnival-themed private islands as they try to respond to strong demand among cruisers for exclusive destinations.

Carnival has committed $600 million to develop Celebration Key, an ambitious private resort destination on Grand Bahama featuring water slides, entertainment venues, and dining establishments. The facility debuts in July.

Bundled packages offering perks like drinks, Wi-Fi, and excursions have encouraged guests to spend more onboard, further boosting revenue for the cruise lines.

The cruise operator reported sales of $6.33 billion for the quarter ended May 31, compared to analysts' estimates of $6.21 billion, according to data compiled by LSEG.

It forecast fiscal 2025 adjusted earnings per share of about $1.97, compared with prior expectations of $1.83.