Stena Line carried 14,000 more passengers between Harwich and the Hook of Holland in the first six months of 2013 compared to the same period last year.
In total, 246,000 passengers used the North Sea crossing, the highest number for six years.
The ferry operator saw a 9.6 per cent lift in cars transported, equivalent to 5,000 more than the prior-year period.
Stena Line also saw a year-on-year increase of 5.7% in coach traffic on the route between January and June.
By comparison, air passenger numbers between the UK and the Netherlands grew less just 2.2%, said the ferry company.
Lars Olsson, Stena Line’s general manager for travel on the North Sea, said, "The Harwich-Hook of Holland service remains of huge strategic importance for Stena Line and we will continue to explore ways to enhance services on the route, ensuring the best possible pricing to sustain our strong growth.
"The ferry link between Harwich and the Hook of Holland reaches its 120th anniversary this year and Stena Line is delighted to play an increasingly significant role in its history and in passenger and freight transportation between Britain and the Netherlands.
"Although we are mindful of the regulatory issues facing ferry travel on the North Sea and the on-going economic challenges affecting the UK and the Eurozone, we remain confident that the hotel-like facilities on board our Superferries, coupled with keen pricing and a convenient schedule, put us in an excellent position to achieve further growth.
"We will continue to work to drive awareness of our services and attract more new customers this year, where we aim to transport in excess of 550,000 passengers and 120,000 cars."
