Brittany Ferries has frozen 2021 prices at 2020 levels in an attempt to urge holidaymakers to consider alternatives to air travel this summer.
The firm sails to France and northern Spain from the UK; both countries were placed on the UK government’s "amber list" on Friday (7 May).
However, it is confident both France and Spain would be bumped up to green status when the traffic light lists undergo their first review in three weeks’ time as more vaccine shots are delivered.
Brittany Ferries said green lights for France and/or Spain would release an "avalanche" of pent-up demand for late June and the peak summer season.
"We want to remind people there are attractive alternatives to air travel this summer,” said Brittany Ferries chief executive Christophe Mathieu.
"Taking the ferry means there’s no need to mingle in a busy terminal building or arrivals hall alongside passengers from multiple destinations. Drive on in your own car, then head straight to a cabin which is fed by fresh sea air.
"Step outside on deck, visit a bar, restaurant or shop, and do so while social distancing in safety and comfort. This is the modern ferry experience and it’s why we urge everyone to consider a sail-and-stay holiday in 2021."
The company said the cost of a voyage in 2021 would be no different to last year, whatever changes the government makes to the traffic light system. It is also offering fully flexible tickets, meaning if the Covid situation changes, customers can change their travel plans "hassle-free".
Brittany Ferries sails from Portsmouth, Poole and Plymouth.