Brittany Ferries is reporting a 29% increase in travel on its Guernsey routes this spring and summer.
Brittany Ferries says - six months into its new 15 year deal - peak-season passenger numbers are up almost a third.
It says it carried 38,500 more people between the UK, Guernsey and France.
Passenger numbers on the UK route were up 9% between April and August, while the French route was up almost 60% on the same time last year.
Boss Christophe Mathieu has credited better-timed and more frequent direct sailings, and joint marketing with Visit Guernsey.
“It is fantastic to see this improvement compared to last year and encouraging that the growth has been consistent across the whole of this summer.
The anticipated rise in visitor numbers – along with longer stays – is delivering clear economic benefits, not just for Guernsey but for the wider Bailiwick."
"It is clear that more and more visitors are opting for sea travel as part of their holiday experience."
Economic Development President Deputy Sasha Kazantseva-Miller will be in St Malo for meetings this week to further boost trade links, food imports and tourism.
A States delegation will attend the Forum Economique Breton, meet port authorities at the Port of St Malo, meet representatives of the St Malo French Chambers of Commerce and Industry (CCI), and the St Malo and Baie du Mont Saint-Michel Tourism, the President and Vice-President of the Regional Council Brittany and key figures from Brittany Ferries.

Number portability issue between Coop Mobile and JT resolved
Guernsey's emergency sleeping pods 'in demand'
Alderney one-step closer to getting a swimming pool
Tickets on sale for women's Muratti
Move to get a full size inflatable pool for Alderney
Three Guernsey seal pups released in spring sunshine
Work begins to clear fallen trees from Guernsey's Reservoir Walk
Guernsey Police to target drivers who put others in danger