Hi, i first picked up on this on a French news website, and the below is pasted from the Brittany Ferries website.
Portsmouth to St Malo - St Malo to Portsmouth
04/12/18 St Malo to Portsmouth 20:30 - Protests in France have closed access to the port in St Malo. We're sorry to advise that this sailing has had to be diverted to OUISTREHAM as a result. The ship will still depart at 20h30, arriving in Portsmouth on schedule. The ongoing protests are creating considerable disruption throughout France so please allow extra time for your journey.
Mike
Portsmouth to St Malo - St Malo to Portsmouth
04/12/18 St Malo to Portsmouth 20:30 - Protests in France have closed access to the port in St Malo. We're sorry to advise that this sailing has had to be diverted to OUISTREHAM as a result. The ship will still depart at 20h30, arriving in Portsmouth on schedule. The ongoing protests are creating considerable disruption throughout France so please allow extra time for your journey.
Mike