The cruise company made a net profit of $49 million, or $0.06 diluted earnings per share in the last quarter, compared to a net loss of $20 million in the last year period.

It attributed its strong earnings to a rise in onboard revenues which were up 8% compared to 2014. Onboard spending rose to $889 million from $850 million, although revenue from ticket prices dropped around 3.5%.

Net revenue yields increased 2% in the first quarter of 2015, better than the company’s December guidance of up to 1%. However, gross revenue yields dropped 3.1% due to changes in currency exchange rates.

Looking ahead to 2015, Carnival Corporation said advance bookings were ahead of 2014 and at higher prices.

Chief executive and president Arnold Donald said: “The year is off to a strong start achieving significantly higher earnings than the prior year and our previous guidance.

“Our onboard revenue initiatives drove particularly strong improvement in the first quarter with onboard yields more than 8% higher than prior year (constant dollar).

“We are experiencing an ongoing improvement in underlying fundamentals based on our successful initiatives to drive demand. Our efforts to further elevate our guest experience are clearly resonating with consumers and, notably, improving the frequency and retention of our loyal guests.”

Donald said he believed results had improved off the back of “ongoing public relations efforts and creative marketing campaigns” designed to attract new customers. He referenced the success of the company’s Super Bowl advertising campaign which generated five billion impressions online before the ad had even run on TV.

He added: “Consistent with many global companies, the strengthening of the US dollar has hampered our full-year earnings expectations, masking the 3% to 4% (constant currency) yield increase our collective brands are expecting to achieve.

“Our successful initiatives to drive both ticket and onboard revenue yields have improved our financial performance and we remain on track toward our goal of achieving double-digit return on invested capital in the next three to four years.”

Folllowing a strong start to the year with bookings, Carnival said it expects full-year 2015 net revenue yields to increase 3% or 4% compared to 2014 and one point better than previous guidance for the year ahead.

However, changes in currency exchange rates means full-year 2015 earning expectations have been reduced by $219 million. Carnival said this was offset by an improvement in the company’s operating performance.