Having committed to pursue net zero greenhouse gas emissions by 2050, 'We're going to do everything we can. We're going to invest vast amounts of money,' Del Rio said during the company's investor day aboard Norwegian Prima in New York.

Whatever it takes

'We're going to do whatever science allows us to do,' he continued. 'We're hoping that biodiesel fuels come along. We're now looking at how to convert several of our newbuilds to methanol fuel, which we believe is the best chance of decarbonization based on the science we have today.'