Norwegian Cruise Line Holdings is looking mostly to exhaust gas scrubbers as the way to satisfy the International Maritime Organization's low-sulphur requirements set for 2020.

"We expect around 65% of our operational capacity in 2020 will have scrubber technology," chief executive Frank Del Rio said today during the company's first-quarter earnings call.

"And then thereafter we will in 2020 and 2021 have additional capacity coming online," he added, responding to a question from Goldman Sachs analyst Stephen Grambling.