Dreamlines is aiming to accelerate its growth with a focus on new markets and additional services following a top-up investment round of €18 million.
The latest backing follows an investment round in August 2016 that brings its total raised during 2016 to €32 million.
The same backers are involved in the round: Holtzbrinck Ventures, Hasso Plattner Ventures, Dimaventures, Altpoint Capital, Target Ventures and Truventuro.
The business has dedicated sites serving Germany, France, the Netherlands, Italy, Russia, Brazil and Australia.
It also has access to 30,000 products from 60 different cruise lines but it also builds packages with cruise, tours, excursions and flights.
It signed a deal with Aeroflot in 2016 to power the cruise channel on the Russian flag carrier's website.
The company says it has reached its "break-even point" for the time on a global scale.
Earlier funding rounds include a €20 million Series C in November 2014 and a Series A and Series B of €2.2 million (2012) and €7.5 million (2013) respectively, bringing its grand total so far to over €70 million.
The package business is now going be extended from its original launch market of Germany to other regions, beginning in Australia.
Managing director Felix Schneider says the growth strategy into 2017 could feature "internal and external options" in its markets, as well as expanding the existing into new countries.
Christian Saller of Holtzbrinck Ventures says:
"We are confident that Dreamlines, a globally operating company, has what it takes to revolutionise cruise bookings, and are fully committed to supporting this growth as much as we can."